Prace polskich(#) (współ)autorów opublikowane w latach 2014 – 2023 wykorzystujące metody rozpraszania neutronów, z wyjątkiem fizyki jądrowej
(#)afiliowanych w polskich instytucjach badawczych
| Baran S, Hoser A, Penc B and Szytuła A (2023), "Magnetoelastic effect in R2Ni2In (R = Tb and Tm) investigated by neutron powder diffraction", Phase Transitions., Feb, 2023. Vol. 96(2), pp. 81-88. |
| Abstract: Magnetoelastic effect in R2Ni2In (R = Tb, Tm), associated with the antiferro- to paramagnetic phase transition at the Néel temperature TN equal to 40 K (R = Tb) or 4.8 K (R = Tm), has been investigated by neutron powder diffraction. Rietveld refinement reveals that the orthorhombic crystal structure, reported at room temperature, is stable down to low temperatures, including magnetically ordered state. Based on the diffraction data, thermal evolution of the lattice parameters a, b and c and the unit cell volume V have been determined. Both the lattice parameters as well as the unit cell volume show distinct jumps in the vicinity of the respective Néel temperatures, indicating presence of the magnetoelastic effect. The values of the lattice strains Δa, Δb, Δc and change of the unit cell volume ΔV, associated with the antiferro- to paramagnetic phase transition, are reported. |
BibTeX:
@article{Baran2023,
author = {Baran, Stanisław and Hoser, Andreas and Penc, Bogusław and Szytuła, Andrzej},
title = {Magnetoelastic effect in R2Ni2In (R = Tb and Tm) investigated by neutron powder diffraction},
journal = {Phase Transitions},
year = {2023},
volume = {96},
number = {2},
pages = {81--88},
url = {https://www.tandfonline.com/doi/full/10.1080/01411594.2023.2188214},
doi = {10.1080/01411594.2023.2188214}
}
|
| Benmohamed M, Guenane H, Messaoudi M, Zahnit W, Egbuna C, Sharifi-Rad M, Chouh A, Seghir BB, Rebiai A, Boubekeur S, Azli T, Harrat M, Sawicka B, Atanassova M and Yousfi M (2023), "Mineral Profile, Antioxidant, Anti-Inflammatory, Antibacterial, Anti-Urease and Anti-α-Amylase Activities of the Unripe Fruit Extracts of Pistacia atlantica", Molecules. Vol. 28(1) MDPI. |
| Abstract: Pistacia Atlantica in folk medicine is used by Algerian traditional healers for treating a wide variety of diseases and conditions including dyspepsia, digestive problems, peptic ulcers, and, in particular, inflammatory diseases. The present study aimed to assess the phytochemical composition, in vitro antioxidant activity (using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ABTS+, and reducing power methods), enzyme inhibitory activity (towards α-amylase and urease), antibacterial activity, and in vivo anti-inflammatory activity of the unripe fruit extracts of Pistacia atlantica collected from different parts of the Djelfa region of Algeria. According to the findings, various aqueous extracts exhibited significant antioxidant and enzymatic activities in all tests, but showed that they have a weak inhibitory effect against all tested bacterial strains. Twenty-one minerals comprising both macro- and microelements (Ba, Br, Ca, Cl, Co, Cr, Cs, Eu, Fe, K, Mg, Mn, Mo, Na, Rb, Sb, Sc, Sr, Th, U, and Zn) were determined using the technique of neutron activation analysis (INAA). The result indicates that the concentration of the mineral element is close to the minimal FAO recommendation. In addition, the result revealed significant anti-inflammatory activities. The data generated can be a valuable source of information for the pharmaceutical industry and medical research. These results suggest that the unripe fruit extracts of Pistacia atlantica have an appropriate potential to be utilized across a wide range of contexts as an agent with multifunctional uses, as well as a natural remedy for other physiological diseases. © 2023 by the authors. |
BibTeX:
@article{Benmohamed2023,
author = {Benmohamed, Mokhtar and Guenane, Hamid and Messaoudi, Mohammed and Zahnit, Wafa and Egbuna, Chukwuebuka and Sharifi-Rad, Majid and Chouh, Amina and Seghir, Bachir Ben and Rebiai, Abdelkrim and Boubekeur, Sihem and Azli, Tarek and Harrat, Mohamed and Sawicka, Barbara and Atanassova, Maria and Yousfi, Mohamed},
title = {Mineral Profile, Antioxidant, Anti-Inflammatory, Antibacterial, Anti-Urease and Anti-α-Amylase Activities of the Unripe Fruit Extracts of Pistacia atlantica},
journal = {Molecules},
publisher = {MDPI},
year = {2023},
volume = {28},
number = {1},
note = {Cited by: 4; All Open Access, Gold Open Access, Green Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85145696487&doi=10.3390%2fmolecules28010349&partnerID=40&md5=29c67e349ae254d99d7ce99225c57c67},
doi = {10.3390/molecules28010349}
}
|
| Brudzińska-Kosior A, Kosior G, Sporek M, Ziembik Z, Zinicovscaia I, Frontasyeva M and Dołhańczuk-Śródka A (2023), "Nuclear analytical techniques used to study the trace element content of Centaurium erythraea Rafn, a medicinal plant species from sites with different pollution loads in Lower Silesia (SW Poland)", PLoS ONE. Vol. 18(5 May) Public Library of Science. |
| Abstract: Centaurium erythraea (Gentianaceae) is a medicinal plant species with therapeutic potential officially listed in the pharmacopoeias of many European, Asian and American countries. It has had many uses in natural medicine since ancient times and it is collected mostly from wild populations. The aim of this study is to investigate the trace element composition of C. erythraea using instrumental neutron activation analysis (INAA). The results of the performed investigations show that INAA has proved to be an efficient analytical technique for the determination of trace elements in medicinal plants. The studied plant contains elements important to the human diet and metabolism that are needed for growth, development and the prevention and curing of disease. A comparison with the reference levels of elements for plants shows that the concentrations of most elements in C. erythraea collected from all types of sites exceed those regarded as the reference. Compared to the values of the elements in C. erythraea from rural areas (LP), the concentrations of most of the investigated elements in C. erythraea collected from the lignite basin, urban areas and in the vicinity of the A4 highway (MP) were significantly higher. The results obtained can be used for control and monitoring in the production of pharmaceuticals based on natural medical plants. © 2023 Brudzińska-Kosior et al. |
BibTeX:
@article{BrudzinskaKosior2023,
author = {Brudzińska-Kosior, Anna and Kosior, Grzegorz and Sporek, Monika and Ziembik, Zbigniew and Zinicovscaia, Inga and Frontasyeva, Marina and Dołhańczuk-Śródka, Agnieszka},
title = {Nuclear analytical techniques used to study the trace element content of Centaurium erythraea Rafn, a medicinal plant species from sites with different pollution loads in Lower Silesia (SW Poland)},
journal = {PLoS ONE},
publisher = {Public Library of Science},
year = {2023},
volume = {18},
number = {5 May},
note = {Cited by: 0; All Open Access, Gold Open Access, Green Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85159755639&doi=10.1371%2fjournal.pone.0285306&partnerID=40&md5=186e79541358e3dc389519de53b4333d},
doi = {10.1371/journal.pone.0285306}
}
|
| Cooper MP, Sharma RP, Magni S, Blach TP, Radliński AP, Drabik K, Tengattini A and Szymczak P (2023), "4D tomography reveals a complex relationship between wormhole advancement and permeability variation in dissolving rocks", Advances in Water Resources. Vol. 175 Elsevier Ltd. |
| Abstract: Dissolution of porous media induces positive feedback between fluid transport and chemical reactions at mineral surfaces, leading to the formation of wormhole-like channels within the rock. Wormholes provide highly efficient flow and transport paths within rock, and as such, understanding their formation is critical for controlling contaminant migration or preventing CO2 leakage during geological carbon sequestration. Here, using time-resolved X-ray tomography, we capture the dynamics of wormhole propagation, inaccessible by standard experimental methods. We find a highly non-trivial relationship between wormhole advancement and variations in permeability of the rock, with extensive periods of steady advancement not reflected by significant change in permeability. This is in contrast to most existing conceptual models where wormholes advance in a linear fashion. We show that this is caused by the presence of highly cemented regions which act as barriers to flow, as confirmed by multi-scale analysis of the pore geometry based on tomographic, (ultra) small angle neutron scattering, and optical microscopy measurements. These results demonstrate that time-lapse captured wormhole dynamics can be used to probe the internal structure of the rock. © 2023 Elsevier Ltd |
BibTeX:
@article{Cooper2023,
author = {Cooper, Max P. and Sharma, Rishabh P. and Magni, Silvana and Blach, Tomasz P. and Radlinski, Andrzej P. and Drabik, Katarzyna and Tengattini, Alessandro and Szymczak, Piotr},
title = {4D tomography reveals a complex relationship between wormhole advancement and permeability variation in dissolving rocks},
journal = {Advances in Water Resources},
publisher = {Elsevier Ltd},
year = {2023},
volume = {175},
note = {Cited by: 2},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85152597570&doi=10.1016%2fj.advwatres.2023.104407&partnerID=40&md5=35f8b52ba77ba27c97a14782e526814d},
doi = {10.1016/j.advwatres.2023.104407}
}
|
| Czub J, Takasaki A, Hoser A, Reehuis M and Gondek Ł (2023), "Synthesis and Hydrogenation of the Ti45−xVxZr38Ni17 (5 ≤ x ≤ 40) Mechanically Alloyed Materials", Energies. Vol. 16(16) Multidisciplinary Digital Publishing Institute (MDPI). |
| Abstract: The mechanically alloyed amorphous alloys of the Ti45Zr38Ni17 composition are known for their ability to form a quasicrystalline state after thermal treatment. It is also known that the amorphous and quasicrystal alloys belonging to the Ti45Zr38Ni17 family are able to store hydrogen and yield gravimetric densities above 2 wt.%. In this contribution, we report the results of research on the Ti45Zr38Ni17 system with vanadium doped instead of titanium. We found that the amorphous samples with moderate doping (x < 20) show the ability to absorb hydrogen while maintaining the amorphous state and they transform into the novel glassy-quasicrystal phase during annealing. Those materials with higher vanadium concentrations do not form entirely amorphous structures. However, they still can absorb hydrogen easily. It was also confirmed that the in situ hydrogenation of the amorphous alloys is a straightforward process without decomposition of the alloy. In this process, hydrogen does not attach to any particular constituent of the alloy, which would lead to the formation of simple hydrides or nanoclusters. Therefore, we were able to confirm the fully amorphous nature of the deuterides/hydrides of the Ti45−xVxZr38Ni17 with moderate V doping. © 2023 by the authors. |
BibTeX:
@article{Czub2023,
author = {Czub, Joanna and Takasaki, Akito and Hoser, Andreas and Reehuis, Manfred and Gondek, Łukasz},
title = {Synthesis and Hydrogenation of the Ti45−xVxZr38Ni17 (5 ≤ x ≤ 40) Mechanically Alloyed Materials},
journal = {Energies},
publisher = {Multidisciplinary Digital Publishing Institute (MDPI)},
year = {2023},
volume = {16},
number = {16},
note = {Cited by: 0; All Open Access, Gold Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85168777384&doi=10.3390%2fen16165857&partnerID=40&md5=1080f4b34d99fe3ab05d85f3baa08cc7},
doi = {10.3390/en16165857}
}
|
| Ghosh P, Guo J, Ye F, Heitmann T, Kelley S, Ernst A, Dugaev V and Singh DK (2023), "NiSi: A New Venue for Antiferromagnetic Spintronics", Advanced Materials. Vol. 35(31) John Wiley and Sons Inc. |
| Abstract: Envisaging antiferromagnetic spintronics pivots on two key criteria of high transition temperature and tuning of underlying magnetic order using straightforward application of magnetic field or electric current. Here, it is shown that NiSi metal can provide suitable new platform in this quest. First, the study unveils high-temperature antiferromagnetism in single-crystal NiSi with Néel temperature, TN ⩾ 700 K. Antiferromagnetic order in NiSi is accompanied by non-centrosymmetric magnetic character with small ferromagnetic component in the a–c plane. Second, it is found that NiSi manifests distinct magnetic and electronic hysteresis responses to field applications due to the disparity in two moment directions. While magnetic hysteresis is characterized by one-step switching between ferromagnetic states of uncompensated moment, electronic behavior is ascribed to metamagnetic switching phenomena between non-collinear spin configurations. Importantly, the switching behaviors persist to high temperature. The properties underscore the importance of NiSi in the pursuit of antiferromagnetic spintronics. © 2023 Wiley-VCH GmbH. |
BibTeX:
@article{Ghosh2023,
author = {Ghosh, Pousali and Guo, Jiasen and Ye, Feng and Heitmann, Thomas and Kelley, Steven and Ernst, Arthur and Dugaev, Vitalii and Singh, Deepak K.},
title = {NiSi: A New Venue for Antiferromagnetic Spintronics},
journal = {Advanced Materials},
publisher = {John Wiley and Sons Inc},
year = {2023},
volume = {35},
number = {31},
note = {Cited by: 0; All Open Access, Green Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85162042100&doi=10.1002%2fadma.202302120&partnerID=40&md5=f403abc1f14eda21c2e0524de2b08054},
doi = {10.1002/adma.202302120}
}
|
| Golub M, Moldenhauer M, Matsarskaia O, Martel A, Grudinin S, Soloviov D, Kuklin A, Maksimov E, Friedrich T and Pieper J (2023), "Stages of OCP-FRP Interactions in the Regulation of Photoprotection in Cyanobacteria, Part 2: Small-Angle Neutron Scattering with Partial Deuteration", J. Phys. Chem. B. Vol. 127(9), pp. 1901-1913. |
| Abstract: We used small-angle neutron scattering partially coupled with size-exclusion chromatography to unravel the solution structures of two variants of the Orange Carotenoid Protein (OCP) lacking the N-terminal extension (OCP-ΔNTE) and its complex formation with the Fluorescence Recovery Protein (FRP). The dark-adapted, orange form OCP-ΔNTEO is fully photoswitchable and preferentially binds the pigment echinenone. Its complex with FRP consists of a monomeric OCP component, which closely resembles the compact structure expected for the OCP ground state, OCPO. In contrast, the pink form OCP-ΔNTEP, preferentially binding the pigment canthaxanthin, is mostly nonswitchable. The pink OCP form appears to occur as a dimer and is characterized by a separation of the N- and C-terminal domains, with the canthaxanthin embedded only into the N-terminal domain. Therefore, OCP-ΔNTEP can be viewed as a prototypical model system for the active, spectrally red-shifted state of OCP, OCPR. The dimeric structure of OCP-ΔNTEP is retained in its complex with FRP. Small-angle neutron scattering using partially deuterated OCP-FRP complexes reveals that FRP undergoes significant structural changes upon complex formation with OCP. The observed structures are assigned to individual intermediates of the OCP photocycle in the presence of FRP. |
BibTeX:
@article{Golub2023,
author = {Golub, M. and Moldenhauer, M. and Matsarskaia, O. and Martel, A. and Grudinin, S. and Soloviov, D. and Kuklin, A. and Maksimov, E.G. and Friedrich, T. and Pieper, J.},
title = {Stages of OCP-FRP Interactions in the Regulation of Photoprotection in Cyanobacteria, Part 2: Small-Angle Neutron Scattering with Partial Deuteration},
journal = {J. Phys. Chem. B},
year = {2023},
volume = {127},
number = {9},
pages = {1901--1913},
doi = {10.1021/acs.jpcb.2c07182}
}
|
| Hao S, Jin W, Bukowski Z, Lin Z, Xiao Y and Su Y (2023), "Canted ferromagnetic order in nonsuperconducting Eu(Fe1−xNix)2As2", Phys. Rev. B., Jan, 2023. Vol. 107(1), pp. 014421. |
| Abstract: The magnetic order in a series of nonsuperconducting Eu(Fe1-xNix)2As2 single crystals is investigated in detail by polarized neutron diffraction. The Fe and Eu magnetic sublattices are found to be almost magnetically decoupled in this system. With the Ni doping, the Eu sublattice shows a dramatic change in its magnetic ground state, from the A-type antiferromagnetic order for x≤0.02, in which the spins lie in the ab plane, to a pure canted ferromagnetic order for 0.04≤x≤0.20, in which the spins are canted with a small angle off the c axis. By comparison with the c-axis perfectly aligned ferromagnetic structure widely observed in other superconducting compounds, the lack of superconductivity in Eu(Fe1-xNix)2As2 might be associated with the formation of in-plane ferromagnetism. The doping-induced change of the lattice constants and accordingly the variation of the strength of indirect Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between the Eu2+ moments is speculated to be responsible for the dramatic change of the Eu spin structure. In addition, a spin reorientation of the Eu2+ moments in an intermediate temperature range is observed for x=0.20, in which some in-plane spin fluctuations persists above the long-range ordering temperature TEu. |
BibTeX:
@article{Hao2023,
author = {Hao, Sijie and Jin, Wentao and Bukowski, Zbigniew and Lin, Zhengwang and Xiao, Yinguo and Su, Yixi},
title = {Canted ferromagnetic order in nonsuperconducting Eu(Fe1−xNix)2As2},
journal = {Phys. Rev. B},
year = {2023},
volume = {107},
number = {1},
pages = {014421},
url = {https://link.aps.org/doi/10.1103/PhysRevB.107.014421},
doi = {10.1103/physrevb.107.014421}
}
|
| Harsányi I, Horváth A, Kis Z, Gméling K, Jóźwiak-Niedzwiedzka D, Glinicki MA and Szentmiklósi L (2023), "Assessment of neutron-induced activation of irradiated samples in a research reactor", Nuclear Engineering and Technology. Vol. 55(3), pp. 1036 – 1044. Korean Nuclear Society. |
| Abstract: The combination of MCNP6 and the FISPACT codes was used to predict inventories of radioisotopes produced by neutron exposure of a sample in a research reactor. The detailed MCNP6 model of the Budapest Research Reactor and the specific irradiation geometry of the NAA channel was established, while realistic material cards were specified based on concentrations measured by PGAA and NAA, considering the precursor elements of all significant radioisotopes. The energy- and spatial distributions of the neutron field calculated by MCNP6 were transferred to FISPACT, and the resulting activities were validated against those measured using neutron-irradiated small and bulky targets. This approach is general enough to handle different target materials, shapes, and irradiation conditions. A general agreement within 10% has been achieved. Moreover, the method can also be made applicable to predict the activation properties of the near-vessel concrete of existing nuclear installations or assist in the optimal construction of new nuclear power plant units. © 2022 Korean Nuclear Society |
BibTeX:
@article{Harsanyi2023,
author = {Harsányi, Ildikó and Horváth, András and Kis, Zoltán and Gméling, Katalin and Jozwiak-Niedzwiedzka, Daria and Glinicki, Michal A. and Szentmiklósi, László},
title = {Assessment of neutron-induced activation of irradiated samples in a research reactor},
journal = {Nuclear Engineering and Technology},
publisher = {Korean Nuclear Society},
year = {2023},
volume = {55},
number = {3},
pages = {1036 – 1044},
note = {Cited by: 1; All Open Access, Gold Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85142676541&doi=10.1016%2fj.net.2022.11.004&partnerID=40&md5=549bd60685f8714523bbf9fc6418964f},
doi = {10.1016/j.net.2022.11.004}
}
|
| Hashemi-Tilehnoee M, Tsirin N, Stoudenets V, Bushuev YG, Chorążewski M, Li M, Li D, Leão JB, Bleuel M, Zajdel P, Del Barrio EP and Grosu Y (2023), "Liquid piston based on molecular springs for energy storage applications", Journal of Energy Storage. Vol. 68 Elsevier Ltd. |
| Abstract: Liquid piston is a method for pressure transmission used in a wide range of technologies. Currently, liquid piston is a passive element solely used to apply pressure to a working body. In this work, the concept of liquid piston based on molecular springs – an active element, which can store a considerable amount of mechanical energy, apart from its main function, which is pressure transmission is proposed. To demonstrate the concept, the Cu2(tebpz) MOF + H2O molecular spring was characterized by employing high-pressure intrusion-extrusion cycling, atomistic simulations, in situ neutrons scattering, scanning electron microscopy and X-ray diffraction. Using compressed air energy storage (CAES) as a case study, it is demonstrated that energy density for this technology can be enhanced ∼5 times by replacing water with a water-based molecular spring. Apart from increased energy density, liquid piston based on molecular spring improves thermal management of CAES systems, enables narrow operational pressure ranges and provides an anti-vibration feature to mitigate undesired vibrations or impacts. The liquid piston based on molecular spring concept can be useful for a broad range of technologies, where pressure transmission is implemented through fluids. © 2023 Elsevier Ltd |
BibTeX:
@article{HashemiTilehnoee2023,
author = {Hashemi-Tilehnoee, Mehdi and Tsirin, Nikolay and Stoudenets, Victor and Bushuev, Yuriy G. and Chorążewski, Mirosław and Li, Mian and Li, Dan and Leão, Juscelino B. and Bleuel, Markus and Zajdel, Paweł and Del Barrio, Elena Palomo and Grosu, Yaroslav},
title = {Liquid piston based on molecular springs for energy storage applications},
journal = {Journal of Energy Storage},
publisher = {Elsevier Ltd},
year = {2023},
volume = {68},
note = {Cited by: 1},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85160400098&doi=10.1016%2fj.est.2023.107697&partnerID=40&md5=cd00a9c202f9dc41f7a5ab10acb657d0},
doi = {10.1016/j.est.2023.107697}
}
|
| Hetmańczyk J, Hetmańczyk Ł, Nitek W and Pawlukojć A (2023), "Thermal, structural, and spectroscopic characterization of an ionic [Cu(H2O)4](ReO4)2 compound in a wide temperature range", J. Raman Spectrosc., Apr, 2023. Vol. 54(4), pp. 434-445. |
| Abstract: We present complementary investigations of water and anion dynamics in an ionic [Cu(H2O)4](ReO4)2. This compound has one reversible phase transition in the solid state upon heating and cooling at 247 and 224 K, respectively. The value of entropy change indicates a moderate degree of molecular dynamical disorder. At room temperature, tetraaquacopper(II) rhenate(VII) crystallizes in a triclinic crystal system, within the space group No. 2 = P-1, with one molecule in the unit cell. X-ray single crystal diffraction measurements indicate that the crystal structure does not change significantly at the phase transition. However, neutron diffraction experiments performed on the powdered sample revealed some subtle changes in the registered patterns. Vibrational–reorientational dynamics of H2O ligands in the high (I) and low-temperature (II) phases of [Cu(H2O)4](ReO4)2 was probed by a set of complementary spectroscopy techniques in a wide temperature range. The dynamics of the H2O molecules in both phases was investigated by means of band shape analysis performed for infrared bands. The H2O ligands perform fast (τR ≈ 10−11 to 10−12 s) stochastic reorientational motions in the phases I and II with a mean value of activation energy: 6.13 kJ⋅mol−1. However, a continuous change of bands connected with hydrogen bonds is observed. The Raman measurements revealed that in the phase transition region the intensity of bands connected with perrhenate anion significantly increases. Using vibrational spectroscopy methods all characteristic wavenumbers of the H2O and ReO4− vibrations were detected. |
BibTeX:
@article{Hetmanczyk2023,
author = {Hetmańczyk, Joanna and Hetmańczyk, Łukasz and Nitek, Wojciech and Pawlukojć, Andrzej},
title = {Thermal, structural, and spectroscopic characterization of an ionic [Cu(H2O)4](ReO4)2 compound in a wide temperature range},
journal = {J. Raman Spectrosc.},
year = {2023},
volume = {54},
number = {4},
pages = {434--445},
url = {https://analyticalsciencejournals.onlinelibrary.wiley.com/doi/10.1002/jrs.6496},
doi = {10.1002/jrs.6496}
}
|
| Jędrzejczyk M, Kopka P, Foad B and Kozłowski T (2023), "Applying approximate Bayesian computation to reduce uncertainty in multigroup 235-U cross-sections using ICSBEP experimental data", Nuclear Engineering and Design. Vol. 414 Elsevier Ltd. |
| Abstract: The multiplication factor (keff) and its uncertainty are critical design parameters in nuclear reactors. The keff uncertainty must be considered for operation, safety, and economic reasons. Consequently, reducing uncertainty in keff has been of interest to the nuclear industry for as long as nuclear reactors were designed. Two methods of reducing this uncertainty are in use – Generalized Linear Least Squares (GLLS) and A General Monte Carlo-Bayes Procedure for Improved Predictions of Integral Functions of Nuclear Data (MOCABA). Both methods have the ability to reduce the keff uncertainty by reducing uncertainty in cross-sections through the assimilation of measured critical systems’ or nuclear reactors’ operational data. The algorithms require means of simulating the experimental data and that the calibrated parameters are described by specific statistical distributions. GLLS is limited to linear models and multivariate normal prior and posterior, while MOCABA can use any (non-linear) model but is also limited to multivariate normal prior and posterior. This work implements a universal and rigorous algorithm called Sequential Monte Carlo – Approximate Bayesian Computation (SMC-ABC) for the same application. It is found that SMC-ABC, GLLS, and likely MOCABA give essentially the same results for the same problems. The paper also presents a reliable method for validating the results based on so-called “synthetic experiments”. Synthetic experiments are computationally generated data used in place of experiments. The method allows for verifying whether there is a risk of overfitting the calibrated parameters (cross-sections in case of this work) during the data assimilation. This novel method shows the potential of using SMC-ABC and other Bayesian calibration methods to generate improved general-purpose neutron cross-section libraries. © 2023 The Authors |
BibTeX:
@article{Jedrzejczyk2023,
author = {Jędrzejczyk, Michał and Kopka, Piotr and Foad, Basma and Kozłowski, Tomasz},
title = {Applying approximate Bayesian computation to reduce uncertainty in multigroup 235-U cross-sections using ICSBEP experimental data},
journal = {Nuclear Engineering and Design},
publisher = {Elsevier Ltd},
year = {2023},
volume = {414},
note = {Cited by: 0; All Open Access, Hybrid Gold Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85167996590&doi=10.1016%2fj.nucengdes.2023.112536&partnerID=40&md5=dfcff74a7aebb2fc22443c09fba27cd6},
doi = {10.1016/j.nucengdes.2023.112536}
}
|
| Juszyńska-Gałązka E and Zając W (2023), "Small angle neutron scattering on n-cyano-3-fluorophenyl 4-butylbenzoates (n = 4,6,8) liquid crystals in mesoporous AAO membranes. A feasibility study", Phase Transitions. Vol. 96(2), pp. 89-96. |
| Abstract: Three mesogenic compounds: n-cyano-3-fluorophenyl 4-butylbenzoates (n = 4,6,8), abbreviated 4CFPB, 6CFPB, and 8CFPB contained in mesoporous Anodic Aluminium Oxide (AAO) membranes were subjected to Small Angle Neutron Scattering measurements with the aim to test the feasibility of SANS experiment as a means of detecting a boundary layer and estimating its thickness. This proved successful for 4CFB and 6CFPB in 18 nm pores, and indicative in 35 nm pores. The thickness of the boundary layer was estimated by core-shell SANS models at ca. 23–26 Å (2.3–2.6 nm). |
BibTeX:
@article{Juszynska-Gaazka2023,
author = {Juszyńska-Gałazka, E. and Zajac, W.},
title = {Small angle neutron scattering on n-cyano-3-fluorophenyl 4-butylbenzoates (n = 4,6,8) liquid crystals in mesoporous AAO membranes. A feasibility study},
journal = {Phase Transitions},
year = {2023},
volume = {96},
number = {2},
pages = {89--96},
doi = {10.1080/01411594.2023.2167656}
}
|
| Kiprono NR, Smoliński T, Rogowski M and Chmielewski AG (2023), "The State of Critical and Strategic Metals Recovery and the Role of Nuclear Techniques in the Separation Technologies Development: Review", Separations. Vol. 10(2) MDPI. |
| Abstract: The extraction of useful minerals or geological materials from the Earth’s crust, most typically from various sources, is crucial to a country’s development and progress. Mineral-rich countries use these resources to transform their economies and propel them toward long-term prosperity. There is an urgent need for the world to increase mineral exploration efforts, improve the recycling of important metal-containing resources, and extract them using upgraded hydrometallurgical procedures with high recovery efficiency. This review paper highlights the importance of strategic and critical metals in the economy and the role of nuclear techniques in the analysis, process optimization, and remediation of metals using solvent extraction, adsorption, and chromatographic resins. Radiotracer analysis, X-Ray Fluorescence spectrometry (XRF), Neutron Activation Analysis (NAA), and X-Ray Diffraction (XRD) are appropriate for improving laboratory-based hydrometallurgical processes, with future technical and economic benefits. The development and installation of novel instruments to provide the real-time control of mining and mineral processing plants for improved control have the potential to aid in the recovery of a broad range of metals. © 2023 by the authors. |
BibTeX:
@article{Kiprono2023,
author = {Kiprono, Nelson R. and Smolinski, Tomasz and Rogowski, Marcin and Chmielewski, Andrzej G.},
title = {The State of Critical and Strategic Metals Recovery and the Role of Nuclear Techniques in the Separation Technologies Development: Review},
journal = {Separations},
publisher = {MDPI},
year = {2023},
volume = {10},
number = {2},
note = {Cited by: 1; All Open Access, Gold Open Access, Green Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85148613404&doi=10.3390%2fseparations10020112&partnerID=40&md5=dc4213dc563be5ab8d63b49516182753},
doi = {10.3390/separations10020112}
}
|
| Kot P, Wroński M, Baczmański A, Ludwik A, Wroński S, Wierzbanowski K, Scheffzük C, Pilch J and Farkas G (2023), "A novel method of experimental determination of grain stresses and critical resolved shear stresses for slip and twin systems in a magnesium alloy", Measurement: Journal of the International Measurement Confederation. Vol. 221 Elsevier B.V.. |
| Abstract: A novel original method of determination of stresses and critical resolved shear stresses (CRSSs) using neutron diffraction was proposed. In this method, based on the crystallite group method, the lattice strains were measured in different directions and using different reflections hkl during uniaxial deformation of magnesium alloy AZ31. The advantage of this method is that the stresses for groups of grains having similar orientations can be determined directly from measurement without any models used for data interpretation. The obtained results are unambiguous and do not depend on the models assumptions as in previous works. Moreover, it was possible for the first time to determine the uncertainty of the measured CRSS values and local stresses at groups of grains. The used methodology allowed for the determination of stress partitioning between grains having different orientations and for an explanation of the anisotropic mechanical behaviour of the strongly textured alloy. Finally, the CRSS values allowed for the validation of the type of intergranular interaction assumed in the elastic–plastic self-consistent model and for a significant reduction of the number of unknown parameters when the model is adjusted to the experimental data. © 2023 The Authors |
BibTeX:
@article{Kot2023,
author = {Kot, P. and Wroński, M. and Baczmański, A. and Ludwik, A. and Wroński, S. and Wierzbanowski, K. and Scheffzük, Ch. and Pilch, J. and Farkas, G.},
title = {A novel method of experimental determination of grain stresses and critical resolved shear stresses for slip and twin systems in a magnesium alloy},
journal = {Measurement: Journal of the International Measurement Confederation},
publisher = {Elsevier B.V.},
year = {2023},
volume = {221},
note = {Cited by: 0; All Open Access, Green Open Access, Hybrid Gold Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85171625999&doi=10.1016%2fj.measurement.2023.113469&partnerID=40&md5=bdc4f3a99e6e9766bca3be112c716bfb},
doi = {10.1016/j.measurement.2023.113469}
}
|
| Kozłowski P, Fabrykiewicz P, Sosnowska I, Fauth F, Senyshyn A, Suard E, Oleszak D and Przeniosło R (2023), "Monoclinic symmetry of the hcp-type ordered areas in bulk cobalt", Phys. Rev. B., Mar, 2023. Vol. 107(10), pp. 104104. |
| Abstract: The gradual ferromagnetic spin reorientation in hexagonal close packed cobalt (hcp-Co) phase between 230∘C and 330∘C reported for a Co single crystal [Bertaut, Solid State Commun. 1, 81 (1963)0038-109810.1016/0038-1098(63)90039-5] suggests that this phase could not have a hexagonal symmetry. This hypothesis is verified positively by synchrotron radiation diffraction and neutron diffraction on polycrystalline powder cobalt. The analysis of diffraction data has been done by using a specific set of Bragg peaks, which are not sensitive to the stacking faults present in abundance in hcp-Co. The crystal structure of the hcp-type ordered areas of cobalt is described by the monoclinic symmetry with the magnetic space group C2′/m′. In this monoclinic crystal structure the former hexagonal [001] axis is no longer perpendicular to the hexagonal layers. The hexagonal [001] and [010] axes make an angle equal α≈ 90.10(1)∘, while the angle between in-plane [100] and [010] axes equals γ≈ 120.11(1)∘. The monoclinic symmetry provides an approximate description of the crystal structure of the stacking faulted hcp-Co areas coexisting with fcc-Co areas. |
BibTeX:
@article{Kozowski2023,
author = {Kozłowski, Paweł and Fabrykiewicz, Piotr and Sosnowska, Izabela and Fauth, François and Senyshyn, Anatoliy and Suard, Emmanuelle and Oleszak, Dariusz and Przeniosło, Radosław},
title = {Monoclinic symmetry of the hcp-type ordered areas in bulk cobalt},
journal = {Phys. Rev. B},
year = {2023},
volume = {107},
number = {10},
pages = {104104},
url = {https://link.aps.org/doi/10.1103/PhysRevB.107.104104},
doi = {10.1103/PhysRevB.107.104104}
}
|
| Krivyakina E, Poudel B, Li C, Kolesnik S, Dąbrowski B, Mitchell J, Rosenkranz S and Chmaissem O (2023), "Redox Properties of Hexagonal and Cubic Sr0.4Ba0.6Mn0.94Ti0.06O3−δ Investigated by In Situ Neutron Powder Diffraction", Chemistry of Materials. Vol. 35(15), pp. 5895 – 5902. American Chemical Society. |
| Abstract: The synthesis and structural properties of polycrystalline cubic and hexagonal Sr0.4Ba0.6Mn0.94Ti0.06O3−δ have been investigated using a combination of in situ neutron diffraction and thermogravimetric analysis. The experiments were conceived to replicate and explain key synthesis processes involving switching between different reducing and oxidizing atmospheres designed to transform a hexagonal phase into an oxygen-deficient cubic perovskite phase in which Mn ions are in their trivalent oxidation state. Hydrogen reduction of the hexagonal phase first produces a heavily oxygen-deficient hexagonal phase preceding to full decomposition of the material. Remarkable reversible properties of the parent hexagonal structure are observed with the phase recovered within minutes by reoxidation of the material after it was decomposed in hydrogen-containing atmospheres. The partial substitution of large Ba ions at the Sr sites enhances the strains and creates wide channels, enabling the rapid oxidation of the oxygen-deficient cubic phase. The fast oxygen intake results in a phase separation between oxygen-rich and oxygen-poor phases with no evidence for any vacancy-ordered superstructures as those previously seen in the parent Ba- and Ti-free SrMnO3−δ system. © 2023 UChicago Argonne LLC. Published by American Chemical Society |
BibTeX:
@article{Krivyakina2023,
author = {Krivyakina, Elena and Poudel, Bisham and Li, Cheng and Kolesnik, Stanislaw and Dabrowski, Bogdan and Mitchell, J.F. and Rosenkranz, Stephan and Chmaissem, Omar},
title = {Redox Properties of Hexagonal and Cubic Sr0.4Ba0.6Mn0.94Ti0.06O3−δ Investigated by In Situ Neutron Powder Diffraction},
journal = {Chemistry of Materials},
publisher = {American Chemical Society},
year = {2023},
volume = {35},
number = {15},
pages = {5895 – 5902},
note = {Cited by: 0; All Open Access, Hybrid Gold Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85166589939&doi=10.1021%2facs.chemmater.3c00693&partnerID=40&md5=96075547e68a727b855802d82c7e559a},
doi = {10.1021/acs.chemmater.3c00693}
}
|
| Lalik E, Parker SF, Irvine G, da Silva I, Gutmann MJ, Romanelli G, Drużbicki K, Kosydar R and Krzystyniak M (2023), "Hydrogen Spillover in Tungsten Oxide Bronzes as Observed by Broadband Neutron Spectroscopy", Energies. Vol. 16(14) Multidisciplinary Digital Publishing Institute (MDPI). |
| Abstract: Hydrogen spillover is an elusive process, and its characterization, using experimental probes and ab initio modeling, poses a serious challenge. In this work, the nuclear quantum dynamics of hydrogen in a palladium-decorated cubic polymorph of tungsten oxide, Pd/cWO3, are characterized by the technique of neutron Compton scattering augmented by ab initio harmonic lattice modeling. The deeply penetrating nature of the neutron scattering process, the lack of spectroscopic selection rules, the inherent high sensitivity to hydrogen, the high energy and momentum resolution for hydrogen, and the mass selectivity of the technique render the neutron Compton scattering a very potent and unique tool for investigating the local dynamics of hydrogen species in bulk matrices. The total neutron Compton scattering response of hydrogen is described in terms of the hydrogen momentum distribution. The distribution is deconvoluted under the assumption of three pools of hydrogen with distinctly different nuclear quantum dynamical behavior: (i) hydrogen-terminated beta-palladium hydride, (ii) hydrogen in acid centers (OH+ groups) on the surface of the cubic phase of tungsten oxide, and (iii) quasi-free atomic hydrogen inside the saturated hydrogen bronze resulting from the spillover process. The ab initio modeling of lattice dynamics yields theoretical predictions for the values of the widths of proton momentum distributions in the first two hydrogen pools, which allows for obtaining the contribution and the width of the momentum distribution of the quasi-free atomic hydrogen resulting from the hydrogen spillover process. The analysis reveals that the local binding strength of the quasi-free hydrogen is characterized by the values of nuclear momentum distribution width, nuclear kinetic energy, and force constant of the underlying potential of the mean force close to those of free, unconstrained hydrogen atomic species in a gas of non-interacting particles described by the Maxwell–Boltzmann distribution. Moreover, this picture of the local dynamics of the quasi-free hydrogen is consistent with the proton polaron model of hydrogen-induced coloration of bulk hydrogenated WO3. © 2023 by the authors. |
BibTeX:
@article{Lalik2023,
author = {Lalik, Erwin and Parker, Stewart F. and Irvine, Gavin and da Silva, Ivan and Gutmann, Matthias Josef and Romanelli, Giovanni and Drużbicki, Kacper and Kosydar, Robert and Krzystyniak, Matthew},
title = {Hydrogen Spillover in Tungsten Oxide Bronzes as Observed by Broadband Neutron Spectroscopy},
journal = {Energies},
publisher = {Multidisciplinary Digital Publishing Institute (MDPI)},
year = {2023},
volume = {16},
number = {14},
note = {Cited by: 0; All Open Access, Gold Open Access, Green Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85166181419&doi=10.3390%2fen16145496&partnerID=40&md5=ddb4ad450ee041bdd4def017bd6f2cb6},
doi = {10.3390/en16145496}
}
|
| Lis B, Batziou A, Adrymi-Sismani V, Mommsen H, Maran J and Prillwitz S (2023), "POTTERY PRODUCTION, EXCHANGE AND CONSUMPTION IN LATE BRONZE AGE MAGNESIA (THESSALY): RESULTS OF NEUTRON ACTIVATION ANALYSIS OF POTTERY FROM DIMINI, VOLOS (NEA IONIA, KASTRO/PALAIA), PEFKAKIA AND VELESTINO", Annual of the British School at Athens. Vol. 15 Cambridge University Press. |
| Abstract: This article presents the results of Neutron Activation Analysis (NAA) of, altogether, 145 pottery and clay samples deriving from five sites located in the Thessalian region of Magnesia: Dimini, Nea Ionia, Kastro/Palaia (Volos), Pefkakia and Velestino. Chronologically, the sampled pottery covers the entire Late Bronze Age (LBA), with a few samples dating to the Middle Bronze Age. Within this broad chronological range, Mycenaean-type pottery dominates, the majority of it being decorated, with an addition of fine unpainted pottery and such used for transport and cooking. Pottery of non-Mycenaean derivation is represented by a variety of types belonging to the early LBA as well as two classes of the early post-palatial period (i.e. after 1200 BC): Handmade Burnished Ware and Grey Ware. Importantly, samples associated with two pottery kilns at Dimini and Velestino were included in the project, although no kiln wasters were identified. Results of the analysis provide important insights into both local Thessalian pottery production and inter- and intra-regional pottery exchange. Local production utilising clay beds around Dimini is best evidenced, with a distribution of its products reaching beyond Thessaly. Two further chemical patterns appear to be associated with Velestino, while an additional two small chemical groups are likely Thessalian as well. In terms of identified imports, the Argolid stands out as the major source of non-local pottery from the beginning of the LBA until the end of the palatial period. Other regions and production localities play a significantly smaller role as sources of supply. On the basis of the study, for the first time the local production as well as importation of pottery in the region of Magnesia is documented by scientific means, opening new research perspectives and strengthening the region's standing as part of the Mycenaean world. © 2023 Cambridge University Press. All rights reserved. |
BibTeX:
@article{Lis2023c,
author = {Lis, Bartłomiej and Batziou, Anthi and Adrymi-Sismani, Vassiliki and Mommsen, Hans and Maran, Joseph and Prillwitz, Susanne},
title = {POTTERY PRODUCTION, EXCHANGE AND CONSUMPTION IN LATE BRONZE AGE MAGNESIA (THESSALY): RESULTS OF NEUTRON ACTIVATION ANALYSIS OF POTTERY FROM DIMINI, VOLOS (NEA IONIA, KASTRO/PALAIA), PEFKAKIA AND VELESTINO},
journal = {Annual of the British School at Athens},
publisher = {Cambridge University Press},
year = {2023},
volume = {15},
note = {Cited by: 2; All Open Access, Hybrid Gold Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85161411398&doi=10.1017%2fS0068245423000047&partnerID=40&md5=5d02403fea4b6fddb3f667a79761b256},
doi = {10.1017/S0068245423000047}
}
|
| Lis B, Mommsen H and Sterba JH (2023), "Imported pottery at the cemetery of Perati in light of the current results of Neutron Activation Analysis", Journal of Archaeological Science: Reports. Vol. 51 Elsevier Ltd. |
| Abstract: Despite the large number of ceramic vessels found at the cemetery of Perati in East Attica, the amount of imports identified in earlier studies was minimal, thus limiting our ability to investigate external connections of the site based on pottery. The present study attempts to fill this gap by reporting the results of Neutron Activation Analysis of 25 vessels, the majority of which were selected as potential imports to Perati. The analysis identified imports from Central Euboea, Laconia, Argolid, Crete and Cyprus, as well as a higher than usual share of singles and pairs. In addition to the previously recognized imports and the growing evidence for exports of pottery from East Attica, these results make it possible to reconstruct a network of reciprocal connections that the area of Perati had with numerous coastal areas of the Aegean and even beyond. © 2023 Elsevier Ltd |
BibTeX:
@article{Lis2023,
author = {Lis, Bartłomiej and Mommsen, Hans and Sterba, Johannes H.},
title = {Imported pottery at the cemetery of Perati in light of the current results of Neutron Activation Analysis},
journal = {Journal of Archaeological Science: Reports},
publisher = {Elsevier Ltd},
year = {2023},
volume = {51},
note = {Cited by: 0},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85171374475&doi=10.1016%2fj.jasrep.2023.104158&partnerID=40&md5=55b02d75a80b0ef1d9f2252b966a1305},
doi = {10.1016/j.jasrep.2023.104158}
}
|
| Lis B, Mommsen H and Sterba JH (2023), "Production and distribution of White Ware towards the end of Late Bronze Age in Greece", Journal of Archaeological Science: Reports. Vol. 47 Elsevier Ltd. |
| Abstract: This article discusses new evidence concerning the production and distribution of White Ware, a pottery class characterized by its distinct sandy fabric, pale surface and predominantly simple decoration that was in circulation in the Aegean during the two last centuries of the 2nd millennium BCE. After a summary of previous studies and hypotheses concerning its production location(s), results of petrographic and Neutron Activation Analysis for White Ware pottery from Eleon and Lefkandi are presented. They confirm that White Ware from these sites is identical to that of Perati, and that it was most likely produced at the same location. Several lines of evidence, including distribution pattern and most recent discoveries in the area of Perati, designate East Attica the most likely production area for White Ware. © 2022 |
BibTeX:
@article{Lis2023a,
author = {Lis, Bartłomiej and Mommsen, Hans and Sterba, Johannes H.},
title = {Production and distribution of White Ware towards the end of Late Bronze Age in Greece},
journal = {Journal of Archaeological Science: Reports},
publisher = {Elsevier Ltd},
year = {2023},
volume = {47},
note = {Cited by: 4},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85146868006&doi=10.1016%2fj.jasrep.2022.103812&partnerID=40&md5=5bff2c6c9812cb69df04bf0097cbe3cb},
doi = {10.1016/j.jasrep.2022.103812}
}
|
| Lis B, Mommsen H, Sterba JH and Van Damme T (2023), "Regional and interregional networks of ancient Eleon during the early 12th century BCE as seen from the petrographic and neutron activation analyses of pottery", Archaeometry. Vol. 65(5), pp. 987 – 1003. John Wiley and Sons Inc. |
| Abstract: In this article, we present the results of application of petrographic and neutron activation analyses to a group of pottery fragments dating to the 12th century BCE deriving from ancient Eleon (Boeotia, Greece) as a means of investigating regional and interregional networks in which the site participated. Production centres in Boeotia and central Euboea provided, as could be expected, the majority of sampled pottery across various shapes. A number of more distant areas, however, such as eastern Attica, the Cyclades, Macedonia, and western Crete, are also documented in the present study, suggesting their products were available to local consumers at ancient Eleon. These results are discussed with reference to consumer preferences and exchange networks operating at that time. Finally, some of the identified petrographic and chemical groups can be securely identified at the macroscopic level, allowing us to arrive at conclusions pertinent to a substantial part of the entire pottery assemblage. © 2023 The Authors. Archaeometry © 2023 University of Oxford. |
BibTeX:
@article{Lis2023b,
author = {Lis, Bartłomiej and Mommsen, Hans and Sterba, Johannes H. and Van Damme, Trevor},
title = {Regional and interregional networks of ancient Eleon during the early 12th century BCE as seen from the petrographic and neutron activation analyses of pottery},
journal = {Archaeometry},
publisher = {John Wiley and Sons Inc},
year = {2023},
volume = {65},
number = {5},
pages = {987 – 1003},
note = {Cited by: 1},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85150893610&doi=10.1111%2farcm.12864&partnerID=40&md5=92cd778de74e946bace7d3949fbedb12},
doi = {10.1111/arcm.12864}
}
|
| Maciak M, Konior M, Wawszczak D, Majewska A, Brodaczewska K, Piasecki P, Narloch J, Sady M, Olszewski J, Gajewski Z, Kieda C, Dziel T and Iller E (2023), "Physical properties and biological impact of 90Y microspheres prepared by sol-gel method for liver radioembolization", Radiation Physics and Chemistry. Vol. 202 Elsevier Ltd. |
| Abstract: Microspheres for liver radioembolization for human use have high requirements in terms of their toxicity and biocompatibility on the one hand, but also typical properties such as physical and chemical durability or specific activity on the other hand. Developed manufacturing process based on the sol-gel method allowed to obtain spherical, yttrium trioxide grains of fully polycrystalline structure with diameters between 20 μm and 100 μm. The work is focused on a further investigation concerning the Y2O3 microspheres including physical, radiometric, dosimetric, and biological experiments. Neutron activation analysis confirmed a high concentration of radioactive 90Y in the sample. The developed procedure for determining the specific activity of a single microsphere showed that at the time of administration, the activity can be specified at the level of 2600–3200 Bq per microsphere. FLUKA Monte Carlo code was used to prepare model for the calculation of dose distributions at the microscopic level, indicating that locally occurring heterogeneities can lead to cold spots during radioembolization. The data obtained from the simulation enabled analysis of the absorbed dose delivered by gel 90Y2O3 microspheres as a function of radioactivity concentration, initial specific activity, or microsphere concentration in the sample. The reduction in colorectal cancer cell proliferation in vitro confirms the significant influence of beta ray radiation from yttrium-90 trioxide microspheres. Histopathological examination of the distribution of microspheres in the porcine model confirmed the proper location of yttrium trioxide microspheres inside blood vessels in a porcine model. Gel Y2O3 microspheres manufactured using the sol-gel method showed relevant properties, indicating the possible use of microspheres for further biological and preclinical studies. © 2022 The Authors |
BibTeX:
@article{Maciak2023,
author = {Maciak, Maciej and Konior, Marcin and Wawszczak, Danuta and Majewska, Aleksandra and Brodaczewska, Klaudia and Piasecki, Piotr and Narloch, Jerzy and Sady, Maria and Olszewski, Jarosław and Gajewski, Zdzisław and Kieda, Claudine and Dziel, Tomasz and Iller, Edward},
title = {Physical properties and biological impact of 90Y microspheres prepared by sol-gel method for liver radioembolization},
journal = {Radiation Physics and Chemistry},
publisher = {Elsevier Ltd},
year = {2023},
volume = {202},
note = {Cited by: 0; All Open Access, Hybrid Gold Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85138088488&doi=10.1016%2fj.radphyschem.2022.110506&partnerID=40&md5=35b9b835b6dd89ec703350e735e62b42},
doi = {10.1016/j.radphyschem.2022.110506}
}
|
| Mandujano HC, Metta A, Barišić N, Zhang Q, Tabiś W, Muniraju NKC and Nair HS (2023), "Sawtooth lattice multiferroic BeCr2O4: Noncollinear magnetic structure and multiple magnetic transitions", Phys. Rev. Mater., Feb, 2023. Vol. 7(2), pp. 024422. |
| Abstract: Noncollinear magnetic structures and multiple
magnetic phase transitions in a sawtooth lattice antiferromagnet
consisting of Cr3+ are experimentally identified in this work,
thereby proposing the scenario of magnetism-driven ferroelectricity
in a sawtooth lattice. The title compound, BeCr2O4, displays three
magnetic phase transitions at low temperatures - at TN1≈7.5 K, at
TN2≈25 K, and at TN3≈26 K - revealed through magnetic
susceptibility, specific heat, and neutron diffraction in this work.
These magnetic phase transitions are found to be influenced by
externally applied magnetic fields. Isothermal magnetization curves
at low temperatures below the magnetic transitions indicate the
antiferromagnetic nature of BeCr2O4 with two spin-flop-like
transitions occurring at Hc1≈29 kOe and Hc2≈47 kOe. Our
high-resolution x-ray and neutron diffraction studies, performed on
single crystal and powder samples, unambiguously determined the
crystal structure as orthorhombic Pbnm. By performing the magnetic
superspace group analysis of the neutron diffraction data at low
temperatures, the magnetic structure in the temperature range TN3,N2 |
BibTeX:
@article{Mandujano2023,
author = {Mandujano, Hector Cein and Metta, Alejandro and Barišić, Neven and Zhang, Qiang and Tabiś, Wojciech and Muniraju, Naveen Kumar Chogondahalli and Nair, Harikrishnan S.},
title = {Sawtooth lattice multiferroic BeCr2 O4: Noncollinear magnetic structure and multiple magnetic transitions},
journal = {Phys. Rev. Mater.},
year = {2023},
volume = {7},
number = {2},
pages = {024422},
url = {https://link.aps.org/doi/10.1103/PhysRevMaterials.7.024422},
doi = {10.1103/PhysRevMaterials.7.024422}
}
|
| Mandujano HC, Tafere MS, Chogondahalli Muniraju NK, Creason TD, McWhorter TM, Gofryk K, Heitmann TW, Zhang Q, Saparov B and Nair HS (2023), "Magnetic structures and excitations in sawtooth olivine chalcogenides Mn2SiX4 (X = S, Se)", Dalton Transactions. Royal Society of Chemistry. |
| Abstract: The Mn lattice in olivine chalcogenide Mn2SiX4 (X = S, Se) compounds forms a sawtooth, which is of special interest in magnetism owing to the possibility of realizing flat bands in magnon spectra, a key component in magnonics. In this work, we investigate the Mn2SiX4 olivines using magnetic susceptibility, and X-ray and neutron diffraction. We have determined the average and local crystal structures of Mn2SiS4 and Mn2SiSe4 using synchrotron X-ray, neutron diffraction, and X-ray total scattering data followed by Rietveld and pair distribution function analyses. It is found from the pair distribution function analysis that the Mn triangle that constitutes the sawtooth is isosceles in Mn2SiS4 and Mn2SiSe4. The temperature evolution of magnetic susceptibility of Mn2SiS4 and Mn2SiSe4 shows anomalies below 83 K and 70 K, respectively, associated with magnetic ordering. From the neutron powder diffraction measurements the magnetic space groups of Mn2SiS4 and Mn2SiSe4 are found to be Pnma and Pnm′a′, respectively. We find that the Mn spins adopt a ferromagnetic alignment on the sawtooth in both Mn2SiS4 and Mn2SiSe4 but along different crystallographic directions for the S and the Se compounds. From the temperature evolution of Mn magnetic moments obtained from refining neutron diffraction data, the transition temperatures are accurately determined as TN(S) = 83(2) K and TN(Se) = 70.0(5) K. Broad diffuse magnetic peaks are observed in both the compounds, and are prominently seen close to TN, suggesting the presence of a short-range magnetic order. The magnetic excitations studied using inelastic neutron scattering reveal a magnon excitation with an energy corresponding to approximately 4.5 meV in both S and Se compounds. Spin correlations are observed to persist up to 125 K much above the ordering temperature and we suggest the possibility of short-range spin correlations responsible for this. © 2023 The Royal Society of Chemistry. |
BibTeX:
@article{Mandujano2023a,
author = {Mandujano, Hector C. and Tafere, Melaku Sisay and Chogondahalli Muniraju, Naveen Kumar and Creason, Tielyr D. and McWhorter, Timothy M. and Gofryk, Krzysztof and Heitmann, Thomas W. and Zhang, Qiang and Saparov, Bayram and Nair, Harikrishnan S.},
title = {Magnetic structures and excitations in sawtooth olivine chalcogenides Mn2SiX4 (X = S, Se)},
journal = {Dalton Transactions},
publisher = {Royal Society of Chemistry},
year = {2023},
note = {Cited by: 0},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85152094234&doi=10.1039%2fd3dt00052d&partnerID=40&md5=35f50a59f387c0f07ace271f578d1367},
doi = {10.1039/d3dt00052d}
}
|
| McGrogan A, Byrne EL, Guiney R, Headen TF, Youngs TGA, Chrobok A, Holbrey JD and Swadźba-Kwaśny M (2023), "The structure of protic ionic liquids based on sulfuric acid, doped with excess of sulfuric acid or with water", Physical Chemistry Chemical Physics. Vol. 25(14), pp. 9785 – 9795. Royal Society of Chemistry. |
| Abstract: Neutron scattering with isotopic substitution was used to study the structure of concentrated sulfuric acid, and two protic ionic liquids (PILs): a Brønsted-acidic PIL, synthesised using pyridine and excess of sulfuric acid, [Hpy][HSO4]·H2SO4, and a hydrated PIL, in which an equimolar mixture of sulfuric acid and pyridine has been doped with water, [Hpy][HSO4]·2H2O. Brønsted acidic PILs are excellent solvents/catalysts for esterifications, driving reaction to completion by phase-separating water and ester products. Water-doped PILs are efficient solvents/antisolvents in biomass fractionation. This study was carried out to provide an insight into the relationship between the performance of PILs in the two respective processes and their liquid structure. It was found that a persistent sulfate/sulfuric acid/water network structure was retained through the transition from sulfuric acid to PILs, even in the presence of 2 moles (∼17 wt%) of water. Hydrogen sulfate PILs have the propensity to incorporate water into hydrogen-bonded anionic chains, with strong and directional hydrogen bonds, which essentially form a new water-in-salt solvent system, with its own distinct structure and physico-chemical properties. It is the properties of this hydrated PIL that can be credited both for the good performance in esterification and beneficial solvent/antisolvent behaviour in biomass fractionation. © 2023 The Royal Society of Chemistry. |
BibTeX:
@article{McGrogan2023,
author = {McGrogan, Anne and Byrne, Emily L. and Guiney, Robert and Headen, Thomas F. and Youngs, Tristan G. A. and Chrobok, Anna and Holbrey, John D. and Swadźba-Kwaśny, Małgorzata},
title = {The structure of protic ionic liquids based on sulfuric acid, doped with excess of sulfuric acid or with water},
journal = {Physical Chemistry Chemical Physics},
publisher = {Royal Society of Chemistry},
year = {2023},
volume = {25},
number = {14},
pages = {9785 – 9795},
note = {Cited by: 1; All Open Access, Green Open Access, Hybrid Gold Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85152170118&doi=10.1039%2fd2cp04292d&partnerID=40&md5=a89f097cc80d3b510aa9c07fe036d6e8},
doi = {10.1039/d2cp04292d}
}
|
| Pajzderska A, Wierzchowski M, Łażewski D, Gielara-Korzańska A, Korzański A, Popenda Ł, Jenczyk J, Juranyi F, Embs JP and Wąsicki J (2023), "Experimental and theoretical insights into the structure and molecular dynamics of 2,3,3′,4′-tetramethoxy-trans-stilbene - a chemopreventive agent", Physical Chemistry Chemical Physics. Vol. 25(27), pp. 18481 – 18494. Royal Society of Chemistry. |
| Abstract: The methoxy analogue of a trans-stilbene compound - 2,3,3′,4′-tetramethoxy-trans-stilbene - was selected to characterize its crystallographic structure, intermolecular interactions and molecular dynamics. The sample was studied using single-crystal X-ray diffraction (XRD), infrared spectroscopy (FT-IR), liquid and solid-state 1H and 13C nuclear magnetic resonance (NMR) and quasielastic neutron scattering (QENS). The compound crystallized in the orthorhombic Pbca space group. The experimental methods were supported by theoretical calculations, density functional theory (plane-wave DFT) and molecular dynamics simulations (MD) methods. Combining several experimental and simulation techniques allowed the detailed analysis of molecular reorientations and provided a consistent picture of the molecular dynamics. The internal molecular mobility of the studied compound can be associated with the reorientational dynamics of four methyl groups. Interestingly, a large diversity of the energy barriers was observed - one methyl group reoriented across low activation barriers (∼3 kJ mol−1), while three methyl groups exhibited a high activation energy (10-14 kJ mol−1) and they are characterised by very different correlation times differing by almost two orders of magnitude at room temperature. The intramolecular interactions mainly influence the activation barriers. © 2023 The Royal Society of Chemistry. |
BibTeX:
@article{Pajzderska2023,
author = {Pajzderska, Aleksandra and Wierzchowski, Marcin and Łażewski, Dawid and Gielara-Korzańska, Agnieszka and Korzański, Artur and Popenda, Łukasz and Jenczyk, Jacek and Juranyi, Fanni and Embs, Jan P. and Wąsicki, Jan},
title = {Experimental and theoretical insights into the structure and molecular dynamics of 2,3,3′,4′-tetramethoxy-trans-stilbene - a chemopreventive agent},
journal = {Physical Chemistry Chemical Physics},
publisher = {Royal Society of Chemistry},
year = {2023},
volume = {25},
number = {27},
pages = {18481 – 18494},
note = {Cited by: 0},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85164281072&doi=10.1039%2fd3cp01747h&partnerID=40&md5=ce13746b39c35ff6b6ce34e4944638eb},
doi = {10.1039/d3cp01747h}
}
|
| Quintero-Castro DL, Nilsen GJ, Meier-Kirchner K, Benitez-Castro A, Guenther G, Sakakibara T, Tokunaga M, Agu C, Mandal I and Tsirlin AA (2023), "One-dimensional magnetism in synthetic Pauflerite, β-VOSO4", Physical Review Materials. Vol. 7(4) American Physical Society. |
| Abstract: We have synthesized single-crystal samples of β-VOSO4 and fully characterized their magnetic properties. Our magnetic susceptibility, high field magnetization, and powder inelastic neutron scattering results are in excellent agreement with theoretical expressions for a one-dimensional spin-1/2 Heisenberg chain with an exchange parameter of 3.83(2) meV. Ab initio calculations identify the superexchange pathway, revealing that the spin-chain does not run along the expected crystallographic chain a direction but instead between V4+O6 octahedra that are linked via SO4 tetrahedra along the b axis. We do not detect any phase transition to a long-range magnetic order within our experimental conditions, indicating β-VOSO4 is very close to an ideal one-dimensional magnetic system. © 2023 American Physical Society. |
BibTeX:
@article{QuinteroCastro2023,
author = {Quintero-Castro, Diana Lucia and Nilsen, Gøran J. and Meier-Kirchner, Katrin and Benitez-Castro, Angelica and Guenther, Gerrit and Sakakibara, Toshiro and Tokunaga, Masashi and Agu, Chidozie and Mandal, Ipsita and Tsirlin, Alexander A.},
title = {One-dimensional magnetism in synthetic Pauflerite, β-VOSO4},
journal = {Physical Review Materials},
publisher = {American Physical Society},
year = {2023},
volume = {7},
number = {4},
note = {Cited by: 0; All Open Access, Green Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85153483255&doi=10.1103%2fPhysRevMaterials.7.045003&partnerID=40&md5=9927ae5093ec5feaef2561de50a10f35},
doi = {10.1103/PhysRevMaterials.7.045003}
}
|
| Radliński AP and Blach T (2023), "Multiscale micro-architecture of pore space in rocks: size, shape, deformation and accessibility determined by small-angle neutron scattering (SANS)", European Physical Journal E. Vol. 46(9) Springer Science and Business Media Deutschland GmbH. |
| Abstract: A brief summary of the evolving applications of small-angle neutron scattering (SANS) to the microstructural research on geological materials in the last few decades is provided, including new developments and possible future directions. This is an account of authors’ view of the interplay between the technical development of SANS instrumentation, methodology and sample environments and the progress of research on the evolution of organic matter, gas adsorption and desorption, fluid transport in the pore space and the microstructure of rocks, based mostly on their own research interests. Graphical abstract: [Figure not available: see fulltext.] © 2023, The Author(s). |
BibTeX:
@article{Radlinski2023,
author = {Radlinski, Andrzej P. and Blach, Tomasz},
title = {Multiscale micro-architecture of pore space in rocks: size, shape, deformation and accessibility determined by small-angle neutron scattering (SANS)},
journal = {European Physical Journal E},
publisher = {Springer Science and Business Media Deutschland GmbH},
year = {2023},
volume = {46},
number = {9},
note = {Cited by: 0; All Open Access, Hybrid Gold Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85170191110&doi=10.1140%2fepje%2fs10189-023-00336-0&partnerID=40&md5=2d66054480a3d7ad99f6ebfa813213ff},
doi = {10.1140/epje/s10189-023-00336-0}
}
|
| Roman M, Fritthum M, Stöger B, Adroja DT and Michor H (2023), "Charge density wave and crystalline electric field effects in TmNiC2", Phys. Rev. B., Mar, 2023. Vol. 107(12), pp. 125137. |
| Abstract: Single crystals of TmNiC2 were grown by the optical floating-zone technique and were investigated by x-ray diffraction (XRD), thermal expansion, electrical resistivity, specific heat, and magnetic susceptibility measurements. Single-crystal XRD reveals the formation of a commensurate charge density wave (CDW) characterized by a CDW modulation vector q2c=(0.5,0.5,0.5), which is accompanied by a symmetry change from the orthorhombic space group Amm2 to the monoclinic space group Cm, i.e., to a CDW superstructure which is isostructural with that of LuNiC2. For all transport and thermodynamic properties, anomalies related to a second order-type thermodynamic CDW phase transition are observed at around TCDW≃375K. The large specific heat anomaly at TCDW, ΔC≃6.2Jmol-1K-1, together with noticeable changes in entropy and enthalpy related to the CDW transition, suggests that this point group symmetry breaking CDW phase transition affects more significant parts of the Fermi surface as compared to the incommensurate CDW transition of, e.g., SmNiC2 with no change in point group symmetry. The results on the antiferromagnetic and paramagnetic state of TmNiC2 obtained by the above macroscopic techniques were complemented by microscopic studies via inelastic neutron scattering. A crystalline electric field modeling of macroscopic susceptibility and magnetic specific heat and entropy contributions as well as microscopic neutron scattering data, reveal crystal field eigenstates and eigenvalues with a ground-state doublet of the Tm-4f electrons, which is well separated by about 25 meV from exited states of the J=6 ground-state multiplet. |
BibTeX:
@article{Roman2023,
author = {Roman, Marta and Fritthum, Maria and Stöger, Berthold and Adroja, Devashibhai T. and Michor, Herwig},
title = {Charge density wave and crystalline electric field effects in TmNiC2},
journal = {Phys. Rev. B},
year = {2023},
volume = {107},
number = {12},
pages = {125137},
url = {https://link.aps.org/doi/10.1103/PhysRevB.107.125137},
doi = {10.1103/PhysRevB.107.125137}
}
|
| Rotnicki K, Sterczyńska A, Fojud Z, Jażdżewska M, Beskrovnyi A, Waliszewski J, Beguin F and Śliwińska-Bartkowiak M (2023), "The effect of pore size of the nanoporous activated carbon on the thermal behavior of confined 1–ethyl–3–methylimidazolium bis(trifluorosulfonyl)imide [EMIM TFSI]", J. Mol. Liq., Mar, 2023. Vol. 373, pp. 121177. |
| Abstract: We report the melting behavior of ionic liquid 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM TFSI) confined in nanoporous carbons. The ionic liquids (ILs) are recently mentioned as promising substances in electrochemistry as electrolytes in supercapacitors. The investigation of melting behavior of applied ionic liquid is important for low temperature operation conditions for supercapacitors. In this work, we presented the experimental studies of the melting behavior of EMIM TFSI confined in carbon micropores of about 1.4 nm pore size and also carbon mesopores of pore size of 4.6 nm. The methods of Dielectric Relaxation Spectroscopy (DRS) and Differential Scanning Calorimetry (DSC) in wide temperature ranges were applied. To investigate structural properties of the systems, temperature-controlled Wide-angle X-ray scattering (WAXS) and Neutron Diffraction (ND) methods were adopted. The results obtained from DSC and DRS indicate that the melting temperature of EMIM TFSI confined in carbon nanopores decrease relative to the bulk ionic liquid. Analysis of the structures and dielectric relaxation processes of the EMIM TFSI below their pore melting point indicates the different structure and slower dynamic of EMIM TFSI confined in pores relative to the bulk. |
BibTeX:
@article{Rotnicki2023,
author = {Rotnicki, Konrad and Sterczyńska, Angelina and Fojud, Zbigniew and Jażdżewska, Monika and Beskrovnyi, Anatolii and Waliszewski, Janusz and Beguin, Francois and Śliwińska-Bartkowiak, Małgorzata},
title = {The effect of pore size of the nanoporous activated carbon on the thermal behavior of confined 1–ethyl–3–methylimidazolium bis(trifluorosulfonyl)imide [EMIM TFSI]},
journal = {J. Mol. Liq.},
year = {2023},
volume = {373},
pages = {121177},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167732222027167},
doi = {10.1016/j.molliq.2022.121177}
}
|
| Scarperi A, Carignani E, Martini F, Embs J, Wąsicki J, Barcaro G, Geppi M and Pajzderska A (2023), "Different Dynamic Behavior of Methyl Groups in Crystalline Carbimazole as Revealed by a Multitechnique Experimental and Theoretical Approach", J. Phys. Chem. C. Vol. 127(10), pp. 5186-5196. |
| Abstract: Dynamic properties of carbimazole (a drug used in hyperthyroidism treatment) were thoroughly investigated by combining solid-state nuclear magnetic resonance spectroscopy and quasielastic neutron scattering with periodic density functional theory (plane-wave DFT) and molecular dynamics simulations. These complementary methods allowed the full description of internal carbimazole motions. Particularly, in crystalline carbimazole, only the reorientations of the two methyl groups were found to be active in the explored timescale. The combination of different techniques allowed the quantitative characterization of the two methyl reorientations, which differ by almost 2 orders of magnitude in the timescale, in agreement with results previously reported in the literature for methyl groups in similar chemical environments. These results could also assume a particular relevance considering the role of methyl groups in determining the biochemical and biological activities of active pharmaceutical ingredients. |
BibTeX:
@article{Scarperi2023,
author = {Scarperi, A. and Carignani, E. and Martini, F. and Embs, J.P. and Wasicki, J. and Barcaro, G. and Geppi, M. and Pajzderska, A.},
title = {Different Dynamic Behavior of Methyl Groups in Crystalline Carbimazole as Revealed by a Multitechnique Experimental and Theoretical Approach},
journal = {J. Phys. Chem. C},
year = {2023},
volume = {127},
number = {10},
pages = {5186--5196},
doi = {10.1021/acs.jpcc.3c00904}
}
|
| Skokowski P, Synoradzki K, Reiffers M, Dzubinska A, Rols S, Arapan S, Legut D and Toliński T (2023), "Effect of transition metals on the crystal field in CeCo0.4Fe0.6Ge3", Intermetallics., Feb, 2023. Vol. 153, pp. 107776. |
| Abstract: We present an investigation of the influence of the 3d elements, Co and Fe, on the interactions between magnetic Ce atoms in the CeCo0.4Fe0.6Ge3 alloy, the member of the CeCo1−xFexGe3 series. The investigated alloy crystallizes in the noncentrosymmetric tetragonal BaNiSn3-type structure (space group I4mm, No. 107), in which the Co and Fe atoms occupy the same 2a position. The close vicinity to the quantum critical point for this alloy was indicated based on previous reports and confirmed by our low temperature resistivity measurements presented in this article. The role of Co and Fe atoms in this alloy was deduced from the scheme of the crystal field levels employing inelastic neutron scattering, specific heat, and magnetic susceptibility. For the analysis, samples LaCoGe3, LaFeGe3, and LaCo0.4Fe0.6Ge3 were used as non-magnetic analogs. The obtained results for CeCo0.4Fe0.6Ge3 alloy were compared with those for CeCoGe3 and CeFeGe3 compounds to emphasize the observed changes in physical properties. The specific heat results are supported by the first-principles calculations. The analysis indicated that the excitation levels of Ce ions are different for the Co- and Fe-rich neighborhood. Based on this information, we can conclude that the 3d elements provide the same energies of RKKY and Kondo interactions for the nearest Ce ions, but their energies for the further ions are lowered due to the presence of other 3d elements. |
BibTeX:
@article{Skokowski2023,
author = {Skokowski, P. and Synoradzki, K. and Reiffers, M. and Dzubinska, A. and Rols, S. and Arapan, S. and Legut, D. and Toliński, T.},
title = {Effect of transition metals on the crystal field in CeCo0.4Fe0.6Ge3},
journal = {Intermetallics},
year = {2023},
volume = {153},
pages = {107776},
url = {https://linkinghub.elsevier.com/retrieve/pii/S096697952200317X},
doi = {10.1016/j.intermet.2022.107776}
}
|
| Szpotkowski K, Wójcik K and Kurzyńska-Kokorniak A (2023), "Structural studies of protein–nucleic acid complexes: A brief overview of the selected techniques", Computational and Structural Biotechnology Journal. Vol. 21, pp. 2858 – 2872. Elsevier B.V.. |
| Abstract: Protein–nucleic acid complexes are involved in all vital processes, including replication, transcription, translation, regulation of gene expression and cell metabolism. Knowledge of the biological functions and molecular mechanisms beyond the activity of the macromolecular complexes can be determined from their tertiary structures. Undoubtably, performing structural studies of protein-nucleic acid complexes is challenging, mainly because these types of complexes are often unstable. In addition, their individual components may display extremely different surface charges, causing the complexes to precipitate at higher concentrations used in many structural studies. Due to the variety of protein-nucleic acid complexes and their different biophysical properties, no simple and universal guideline exists that helps scientists chose a method to successfully determine the structure of a specific protein-nucleic acid complex. In this review, we provide a summary of the following experimental methods, which can be applied to study the structures of protein-nucleic acid complexes: X-ray and neutron crystallography, nuclear magnetic resonance (NMR) spectroscopy, cryogenic electron microscopy (cryo-EM), atomic force microscopy (AFM), small angle scattering (SAS) methods, circular dichroism (CD) and infrared (IR) spectroscopy. Each method is discussed regarding its historical context, advancements over the past decades and recent years, and weaknesses and strengths. When a single method does not provide satisfactory data on the selected protein–nucleic acid complex, a combination of several methods should be considered as a hybrid approach; thus, specific structural problems can be solved when studying protein-nucleic acid complexes. © 2023 The Author(s) |
BibTeX:
@article{Szpotkowski2023,
author = {Szpotkowski, Kamil and Wójcik, Klaudia and Kurzyńska-Kokorniak, Anna},
title = {Structural studies of protein–nucleic acid complexes: A brief overview of the selected techniques},
journal = {Computational and Structural Biotechnology Journal},
publisher = {Elsevier B.V.},
year = {2023},
volume = {21},
pages = {2858 – 2872},
note = {Cited by: 0; All Open Access, Gold Open Access, Green Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85156249948&doi=10.1016%2fj.csbj.2023.04.028&partnerID=40&md5=66c05e7a3b44bd9abf2dbf78920e279d},
doi = {10.1016/j.csbj.2023.04.028}
}
|
| Tripodi S, Toro MD, Rejdak R, Costagliola C, Avitabile T, Carnevali A, Bruzzichessi D, Gambaro S and Porta A (2023), "Qualitative and quantitative analysis of an explanted opacified hydrophilic IOL after over two years from cataract surgery", European Journal of Ophthalmology. SAGE Publications Ltd. |
| Abstract: Opacification of hydrophilic intraocular lenses (IOLs) is an uncommon complication, that can appear after uneventful cataract surgery. We report a case of opacified Hydroview® IOL in a 76-year-old woman, with a previous history of pars plana vitrectomy with silicon oil tamponade in her right eye for a proliferative diabetic retinopathy, who developed an opacification of the IOL after over two years from a silicon oil/BSS exchange in combination with an uneventful phacoemulsification. The patient complained about a progressive decrease in her visual acuity. The slit-lamp examination confirmed the opacification of the IOL. Therefore, because of blurred vision, a combined procedure of explant and exchange of the IOL was performed in the same eye. Qualitative (Optic microscope, X-Ray powder Diffraction (XRD), Scanning Electron Microscopy (SEM)) and quantitative (Instrumental Neutron Activation Analysis (INAA)) analysis of the IOL material were performed. Here, our aim is to report the acquired data of the explanted Hydroview® H60M IOL. © The Author(s) 2023. |
BibTeX:
@article{Tripodi2023,
author = {Tripodi, Sarah and Toro, Mario Damiano and Rejdak, Robert and Costagliola, Ciro and Avitabile, Teresio and Carnevali, Adriano and Bruzzichessi, Donatella and Gambaro, Stefano and Porta, Alessandro},
title = {Qualitative and quantitative analysis of an explanted opacified hydrophilic IOL after over two years from cataract surgery},
journal = {European Journal of Ophthalmology},
publisher = {SAGE Publications Ltd},
year = {2023},
note = {Cited by: 0; All Open Access, Hybrid Gold Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85149908054&doi=10.1177%2f11206721221145744&partnerID=40&md5=7255ed382357f08baa60ed968ab49f45},
doi = {10.1177/11206721221145744}
}
|
| Tomchuk OV, Kryshtal OP, Juszyńska-Gałązka E and Zając WM (2023), "Particle-size polydispersity analysis based on the unified exponential/power-law approach to small-angle scattering", Journal of Applied Crystallography., Aug, 2023. Vol. 56(4), pp. 1099-1107. |
| Abstract: Controlling particle dispersity is of huge importance for practical applications in nanoscience and technology. The analysis of small-angle scattering of X-rays and neutrons for strongly polydisperse particulate systems is considered from the point of view of describing the type of size distribution function without applying classical regularization approaches. This article presents the development of a method for determining the polydispersity parameters of nanoobjects, based on the analysis of the ratio of various moments of the size distribution function, which are proportional to different invariants of the scattering curve. The use of the unified exponential/power-law approximation to describe small-angle scattering data makes it possible to determine the type of distribution, the average size and the spread. The possibilities of the method were tested for several hydro-sols of metallic nanoparticles. |
BibTeX:
@article{Tomchuk2023,
author = {Tomchuk, Oleksandr V. and Kryshtal, Oleksandr P. and Juszyʼnska-Gałazka, Ewa and Zajac, Wojciech M.},
title = {Particle-size polydispersity analysis based on the unified exponential/power-law approach to small-angle scattering},
journal = {Journal of Applied Crystallography},
year = {2023},
volume = {56},
number = {4},
pages = {1099--1107},
url = {https://doi.org/10.1107/S1600576723004752},
doi = {10.1107/S1600576723004752}
}
|
| Wang X, Zhang X, Tong P, Yang C, Si J, Xiong T, Dong B, Xie L, Pan C, Wang M, Lin J, Chen H, Yin W, Song W and Sun Y (2023), "Latent heat thermal storage of solid-state phase transition in thermally stabilized hexagonal FeS", Scr. Mater., Mar, 2023. Vol. 225, pp. 115166. |
| Abstract: Large amounts of heat are required in areas such as food processing and textile industries to maintain equipment in the medium-temperature zone 393–573 K. However, thermal storage materials that work at this temperature are rare. Hexagonal iron sulfide FeS exhibits a solid-state phase transition at 420 K, accompanied by a high entropy change. The quenched FeS is unstable when subjected to a thermal cycling test, and the related entropy change declines. A secondary hexagonal phase with Fe deficiency was confirmed by neutron powder diffractions. Annealing FeS at temperatures slightly higher than Tt can accelerate the formation of the secondary phase. Once the sample is stabilized, the entropy change is no longer changeable. The thermally stabilized FeS sample exhibits a relatively high thermal storage density up to 136 J/cm3. This work suggests a new solid candidate for the application of solid-state phase transition latent heat energy storage in the medium-temperature region. |
BibTeX:
@article{Wang2023,
author = {Wang, Xuelian and Zhang, Xuekai and Tong, Peng and Yang, Cheng and Si, Jianguo and Xiong, Tingjiao and Dong, Buke and Xie, Lulu and Pan, Chengbing and Wang, Meng and Lin, Jianchao and Chen, Huaican and Yin, Wen and Song, Wenhai and Sun, Yuping},
title = {Latent heat thermal storage of solid-state phase transition in thermally stabilized hexagonal FeS},
journal = {Scr. Mater.},
year = {2023},
volume = {225},
pages = {115166},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1359646222006613},
doi = {10.1016/j.scriptamat.2022.115166}
}
|
| Wilkinson JM, Blundell SJ, Biesenkamp S, Braden M, Hansen TC, Koteras K, Grochala W, Barone P, Lorenzana J, Mazej Z and Tavčar G (2023), "Low-temperature magnetism of KAgF3", Physical Review B. Vol. 107(14) American Physical Society. |
| Abstract: KAgF3 is a quasi-one-dimensional quantum
antiferromagnet hosting a series of intriguing structural and
magnetic transitions. Here we use powder neutron diffraction, μSR
spectroscopy, and density functional theory calculations to
elucidate the low-temperature magnetic phases. Below TN1=29K we find
that the material orders as an A-type antiferromagnet with an
ordered moment of 0.52μB. Both neutrons and muons provide evidence
for an intermediate phase at temperatures TN1 |
BibTeX:
@article{Wilkinson2023,
author = {Wilkinson, John M. and Blundell, Stephen J. and Biesenkamp, Sebastian and Braden, Markus and Hansen, Thomas C. and Koteras, Kacper and Grochala, Wojciech and Barone, Paolo and Lorenzana, José and Mazej, Zoran and Tavčar, Gašper},
title = {Low-temperature magnetism of KAgF3},
journal = {Physical Review B},
publisher = {American Physical Society},
year = {2023},
volume = {107},
number = {14},
note = {Cited by: 0; All Open Access, Green Open Access, Hybrid Gold Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85158819467&doi=10.1103%2fPhysRevB.107.144422&partnerID=40&md5=7b9df38aa4480b2a96010a7c2a64bbda},
doi = {10.1103/PhysRevB.107.144422}
}
|
| Xie L, Shi T, Lin J, Zhang X, Zhong X, Liu K, Dong B, Yang C, Wang X, Xiong T, Song W and Sun Y (2023), "The enhanced negative thermal expansion in less-oxygen-vacancies copper pyrophosphate", J. Mater. Sci. Technol.. Vol. 146, pp. 80-85. |
| Abstract: For oxides, controlling the concentration of oxygen vacancy is a useful way to optimize their functional properties. However, when it comes to the field of negative thermal expansion (NTE), much less attention has been paid to the effect of oxygen vacancy on NTE, though oxide-typed NTE materials account for more than 40% of the total NTE materials. Here, we report that the linear coefficient of thermal expansion at 250–350 K of copper pyrophosphate (i.e., Cu2P2O7) can be significantly improved from –13.88 to –36.60 ppm/K when the synthesis temperature is raised from 1073 to 1373 K. The combined study including X-ray absorption near edge structure, neutron powder diffraction, and X-ray diffraction has confirmed the selective vacancies in the O1 site for low-temperature synthesized samples, which suppress both the phase-transition and framework-structure driven NTE simultaneously. Our result proposes a new approach for optimizing the NTE effect of oxides. |
BibTeX:
@article{Xie2023,
author = {Xie, L.L. and Shi, T.F. and Lin, J.C. and Zhang, X.K. and Zhong, X.K. and Liu, K.K. and Dong, B.K. and Yang, C. and Wang, X.L. and Xiong, T.J. and Song, W.H. and Sun, Y.P.},
title = {The enhanced negative thermal expansion in less-oxygen-vacancies copper pyrophosphate},
journal = {J. Mater. Sci. Technol.},
year = {2023},
volume = {146},
pages = {80--85},
doi = {10.1016/j.jmst.2022.10.054}
}
|
| Yartys V, Vajeeston P, Denys R, Havela L, Maskova-Cerna S and Szytula A (2023), "Bonding mechanism and magnetic ordering in Laves phase λ1−MgCo2 intermetallic compound from theoretical and experimental studies", Scripta Materialia. Vol. 237 Acta Materialia Inc. |
| Abstract: In the present work we have studied the bonding mechanism and magnetism in a hexagonal λ1−MgCo2 Laves phase intermetallic formed at rA/rB= 1.280. Ab initio theoretical calculations for MgCo2 using the projector-augmented wave method implemented in the VASP code showed that Mg carries a formal charge +1.7 |e| while Co atoms are also positively charged with around +0.7 |e| being donated to establish the interatomic covalent Co-Co bonding in a three-dimensional network of Co tetrahedra. MgCo2 is a metallic conductor with ferromagnetic properties and TC=303 K. Neutron Powder Diffraction study showed a collinear ordering of the Co moments, their alignment along the c-axis of the hexagonal unit cell with an average moment of 1.51(2) μB/atom Co. Ab initio computational studies indicate that the Co moments reach the experimentally observed value approx.1.5 μB when the unit cell volume exceeds 160 Å3 (average Co-Co distances 2.43 Å). © 2023 The Author(s) |
BibTeX:
@article{Yartys2023,
author = {Yartys, V.A. and Vajeeston, P. and Denys, R.V. and Havela, L. and Maskova-Cerna, S. and Szytula, A.},
title = {Bonding mechanism and magnetic ordering in Laves phase λ1−MgCo2 intermetallic compound from theoretical and experimental studies},
journal = {Scripta Materialia},
publisher = {Acta Materialia Inc},
year = {2023},
volume = {237},
note = {Cited by: 0; All Open Access, Hybrid Gold Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85167451597&doi=10.1016%2fj.scriptamat.2023.115709&partnerID=40&md5=2dc79dd4f3ad1c96c9dfcf9e7afae8d4},
doi = {10.1016/j.scriptamat.2023.115709}
}
|
| Zhang L, Malys M, Jamróz J, Krok F, Wróbel W, Hull S, Yan H and Abrahams I (2023), "Structure and Conductivity in LISICON Analogues within the Li4GeO4-Li2MoO4 System", Inorganic Chemistry. Vol. 62(30), pp. 11876 – 11886. American Chemical Society. |
| Abstract: New solid electrolytes are crucial for the development of all-solid-state lithium batteries with advantages in safety and energy densities over current liquid electrolyte systems. While some of the best solid-state Li+-ion conductors are based on sulfides, their air sensitivity makes them less commercially attractive, and attention is refocusing on air-stable oxide-based systems. Among these, the LISICON-structured systems, such as Li2+2xZn1-xGeO4 and Li3+xV1-xGexO4, have been relatively well studied. However, other systems such as the Li4GeO4-Li2MoO4 system, which also show LISICON-type structures, have been relatively little explored. In this work, the Li4-2xGe1-xMoxO4 solid solution is investigated systematically, including the solid solution limit, structural stability, local structure, and the corresponding electrical behavior. It is found that a γ-LISICON structured solution is formed in the range of 0.1 ≤ x < 0.4, differing in structure from the two end members, Li4GeO4 and Li2MoO4. With increasing Mo content, the β-phase becomes increasingly more stable than the γ-phase, and at x = 0.5, a pure β-phase (β-Li3Ge0.5Mo0.5O4) is readily isolated. The structure of this previously unknown compound is presented, along with details of the defect structure of Li3.6Ge0.8Mo0.2O4 (x = 0.2) based on neutron diffraction data. Two basic types of defects are identified in Li3.6Ge0.8Mo0.2O4 involving interstitial Li+-ions in octahedral sites, with evidence for these coming together to form larger defect clusters. The x = 0.2 composition shows the highest conductivity of the series, with values of 1.11 × 10-7 S cm-1 at room temperature rising to 5.02 × 10-3 S cm-1 at 250 °C. © 2023 The Authors. Published by American Chemical Society. |
BibTeX:
@article{Zhang2023,
author = {Zhang, Ludan and Malys, Marcin and Jamroz, Jan and Krok, Franciszek and Wrobel, Wojciech and Hull, Stephen and Yan, Haixue and Abrahams, Isaac},
title = {Structure and Conductivity in LISICON Analogues within the Li4GeO4-Li2MoO4 System},
journal = {Inorganic Chemistry},
publisher = {American Chemical Society},
year = {2023},
volume = {62},
number = {30},
pages = {11876 – 11886},
note = {Cited by: 0; All Open Access, Green Open Access, Hybrid Gold Open Access},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85166417055&doi=10.1021%2facs.inorgchem.3c01222&partnerID=40&md5=ba5737a5217483da8e38290343e960a2},
doi = {10.1021/acs.inorgchem.3c01222}
}
|
| Amorese A, Khalyavin D, Kummer K, Brookes NB, Ritter C, Zaharko O, Larsen CB, Pavlosiuk O, Pikul AP, Kaczorowski D, Gutmann M, Boothroyd AT, Severing A and Adroja DT (2022), "Metamagnetism and crystal-field splitting in pseudohexagonal CeRh3Si2", Phys. Rev. B., Mar, 2022. Vol. 105(12), pp. 125119. |
| Abstract: CeRh3Si2 has been reported to exhibit metamagnetic transitions below 5 K, a giant crystal field splitting, and anisotropic magnetic properties from single crystal magnetization and heat capacity measurements. Here we report results of neutron and x-ray scattering studies of the magnetic structure and crystal-field excitations to further understand the magnetism of this compound. Inelastic neutron scattering and resonant inelastic x-ray scattering reveal a Jz=1/2 ground state for Ce when considering the crystallographic a direction as quantization axis, thus explaining the anisotropy of the static susceptibility. Furthermore, we find a total splitting of 78 meV for the J=5/2 multiplet. The neutron diffraction study in zero field reveals that, on cooling from the paramagnetic state, the system first orders at TN1=4.7K in a longitudinal spin density wave with ordered Ce moments along the b axis (i.e., the [0 1 0] crystal direction) and an incommensurate propagation vector k=(0,0.43,0). Below the lower-temperature transition TN2=4.48K, the propagation vector locks to the commensurate value k=(0,0.5,0), with a so-called lock-in transition. Our neutron diffraction study in applied magnetic field Hb axis shows a change in the commensurate propagation vector and development of a ferromagnetic component at H=3kOe, followed by a series of transitions before the fully field-induced ferromagnetic phase is reached at H=7kOe. This explains the nature of the steps previously reported in field-dependent magnetization measurements. A very similar behavior is also observed for the H [0 1 1] crystal direction. |
BibTeX:
@article{Amorese2022,
author = {Amorese, Andrea and Khalyavin, Dmitry and Kummer, Kurt and Brookes, Nicholas B. and Ritter, Clemens and Zaharko, Oksana and Larsen, Camilla Buhl and Pavlosiuk, Orest and Pikul, Adam P. and Kaczorowski, Dariusz and Gutmann, Matthias and Boothroyd, Andrew T. and Severing, Andrea and Adroja, Devashibhai T.},
title = {Metamagnetism and crystal-field splitting in pseudohexagonal CeRh3Si2},
journal = {Phys. Rev. B},
year = {2022},
volume = {105},
number = {12},
pages = {125119},
url = {https://link.aps.org/doi/10.1103/PhysRevB.105.125119},
doi = {10.1103/PhysRevB.105.125119}
}
|
| Bharatiya B, Włodek M, Harniman R, Schweins R, Mantell J, Wang G, Warszyński P and Briscoe WH (2022), "Solution and interfacial self-assembly of Bacillus subtilis bacterial lipoteichoic acid (LTA): nanoclustering, and effects of Ca2+ and temperature", Nanoscale. Vol. 14(34), pp. 12265-12274. |
| Abstract: Lipoteichoic acid (LTA) is a major structural and functional molecule in the Gram-positive bacteria membrane. Knowledge of LTA adsorption at interfaces and its solution self-assembly is crucial to understanding its role in bacterial adhesion and colonisation, infections and inflammations. Here, we report the self-assembly behaviour of LTA extracted from Bacillus subtilis, a Gram-positive bacterium, in an aqueous solution using cryogenic transmission electron microscopy (Cryo-TEM) and small-angle neutron scattering (SANS) and its adsorption behaviour at the solid-liquid interface using atomic force microscopy (AFM) imaging and quartz crystal microbalance with dissipation monitoring (QCM-D). The Cryo-TEM results indicated the formation of spherical LTA micelles that decreased in size on addition of calcium chloride (CaCl2), attributed to charge neutralisation and possible formation of stable Ca2+-bridges between the phosphate groups on neighbouring LTA chains. Analysis of the SANS data from the polydisperse LTA aggregates in solution using the two Lorentzian model revealed the existence of two correlation lengths, which could respectively account for the presence of LTA micelle clusters and the local structure arising from LTA intra-molecular interactions. In the presence of CaCl2, the decrease in the correlation lengths of the clusters indicated possible disruption of H-bonding by Ca2+, leading to poorer water-LTA interactions. At higher temperatures, the correlation length corresponding to the clusters increased, indicating a temperature assisted growth caused by the fluidization of micellar core and dehydration of the polar LTA chains. AFM imaging showed that adsorption of LTA aggregates at the SiO2-water interface was significantly prompted by the addition of CaCl2, also confirmed by QCM-D measurements. These unprecedented nanoscopic structural details on the morphology of LTA aggregates in solution and at the solid-liquid interface add to our fundamental understanding of its self-assembly behaviour hitherto underexplored. |
BibTeX:
@article{Bharatiya2022,
author = {Bharatiya, Bhavesh and Wlodek, Magdalena and Harniman, Robert and Schweins, Ralf and Mantell, Judith and Wang, Gang and Warszynski, Piotr and Briscoe, Wuge H.},
title = {Solution and interfacial self-assembly of Bacillus subtilis bacterial lipoteichoic acid (LTA): nanoclustering, and effects of Ca2+ and temperature},
journal = {Nanoscale},
year = {2022},
volume = {14},
number = {34},
pages = {12265--12274},
url = {http://xlink.rsc.org/?DOI=D2NR00595F},
doi = {10.1039/d2nr00595f}
}
|
| Chodkiewicz M, Gajda R, Lavina B, Tkachev S, Prakapenka V, Dera P, Wozniak K and Lightfoot P (2022), "Accurate crystal structure of ice VI from X-ray diffraction with Hirshfeld atom refinement", IUCrJ. Vol. 9(Pt 5), pp. 573-579. |
| Abstract: Water is an essential chemical compound for living organisms, and twenty of its different crystal solid forms (ices) are known. Still, there are many fundamental problems with these structures such as establishing the correct positions and thermal motions of hydrogen atoms. The list of ice structures is not yet complete as DFT calculations have suggested the existence of additional and - to date - unknown phases. In many ice structures, neither neutron diffraction nor DFT calculations nor X-ray diffraction methods can easily solve the problem of hydrogen atom disorder or accurately determine their anisotropic displacement parameters (ADPs). Here, accurate crystal structures of H2O, D2O and mixed (50%H2O/50%D2O) ice VI obtained by Hirshfeld atom refinement (HAR) of high-pressure single-crystal synchrotron and laboratory X-ray diffraction data are presented. It was possible to obtain O - H/D bond lengths and ADPs for disordered hydrogen atoms which are in good agreement with the corresponding single-crystal neutron diffraction data. These results show that HAR combined with X-ray diffraction can compete with neutron diffraction in detailed studies of polymorphic forms of ice and crystals of other hydrogen-rich compounds. As neutron diffraction is relatively expensive, requires larger crystals which can be difficult to obtain and access to neutron facilities is restricted, cheaper and more accessible X-ray measurements combined with HAR can facilitate the verification of the existing ice polymorphs and the quest for new ones. |
BibTeX:
@article{Chodkiewicz2022,
author = {Chodkiewicz, M.L. and Gajda, R. and Lavina, B. and Tkachev, S. and Prakapenka, V.B. and Dera, P. and Wozniak, K. and Lightfoot, P.},
title = {Accurate crystal structure of ice VI from X-ray diffraction with Hirshfeld atom refinement},
journal = {IUCrJ},
year = {2022},
volume = {9},
number = {Pt 5},
pages = {573--579},
doi = {10.1107/S2052252522006662}
}
|
| Demir E, Popov E, Mirzayev M, Slavov L, Neov D, Donkov A, Siemek K, Vershinina T, Genov I, Beskrovnyi A, Skuratov V, Krezhov K, Horodek P, Mamedov F, Valizade A and Vural Ö (2022), "Effects of swift heavy ions at different fluencies on WC-6Co hard metal alloy", Int. J. Refract. Met. Hard Mater., Aug, 2022. Vol. 106, pp. 105865. |
| Abstract: Tungsten carbide hard metal alloy with 6% by weight cobalt was studied before and after irradiation at different fluencies with 167 MeV132Xe ions. Raman spectroscopy, X-ray diffraction, neutron diffraction and positron lifetime spectroscopy were employed in order to assess the microstructural evolution in the material upon irradiation fluence increase. Analysis of the Raman spectrum for the pristine, non-irradiated material unveils that the surface is composed of a graphite-like phase and highly oxidized tungsten atoms spread in the carbon matrix. All characteristic peaks of tungsten carbide (WC) and possible cobalt phases are either missing or strongly overlapped in all Raman spectra. Bonding between tungsten and oxygen atoms broke upon irradiation and total deoxidation of the surface is detected for the two highest fluencies investigated at 5 × 1013 ions/cm2 and 3,83 × 1014 ions/cm2. Increasing the irradiation dose causes amorphization of the carbon phase on the surface accompanied by “up and down” trend of change in carbon cluster size. The Raman spectra analysis also unveils, that molecular nitrogen (N2) from the atmosphere penetrates the carbon matrix upon irradiation. The results from the X-ray and neutron diffraction reveal that the main phase in the material is δ-WC and also give information about changes of the lattice parameters with increasing fluence. Reorganization of the induced point defects to dislocation defects as a function of the irradiation dose is discussed, but no phase transition of the main δ-WC phase is detected. Steady increase of compressive internal stress with increasing irradiation dose is noted by XRD. The tendency is not monotonic and the stress leans towards saturation at the highest fluence, with the highest value of −5.26 GPa. The Positron lifetime spectroscopy measurements show the presence of short lifetime component ranging from 170 ps to 190 ps, interpreted as small vacancy clusters. The intensities of the different positron lifetime components vary with the irradiation dose non-monotonically. |
BibTeX:
@article{Demir2022,
author = {Demir, Ertuğrul and Popov, Evgeni and Mirzayev, Matlab and Slavov, Lyubomir and Neov, Dimitar and Donkov, Alexander and Siemek, Krzysztof and Vershinina, Tatiana and Genov, Ivaylo and Beskrovnyi, Anatolii and Skuratov, Vladimir and Krezhov, Kiril and Horodek, Pawel and Mamedov, Fadahat and Valizade, Aygul and Vural, Özlem},
title = {Effects of swift heavy ions at different fluencies on WC-6Co hard metal alloy},
journal = {Int. J. Refract. Met. Hard Mater.},
year = {2022},
volume = {106},
pages = {105865},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0263436822000890},
doi = {10.1016/j.ijrmhm.2022.105865}
}
|
| Dinh V-P, Luu TA, Siemek K, Kozlenko DP, Le KH, Dang NT, Nguyen TV, Le Phuc N, Tran TD, Phan PT, Lo ST, Hoang KAT, Dinh TK, Luong NT, Le NC, Nguyen N-T, Ho T-H, Tran XD, Tran PD and Nguyen HQ (2022), "Crystallization Pathways and Evolution of Morphologies and Structural Defects of α-MnO2 under Air Annealing", Langmuir., Dec, 2022. Vol. 38(50), pp. 15604-15613. |
| Abstract: Manganese dioxide nanomaterials have wide applications in many areas from catalysis and Li-ion batteries to gas sensing. Understanding the crystallization pathways, morphologies, and formation of defects in their structure is particularly important but still a challenging issue. Herein, we employed an arsenal of X-ray diffraction (XRD), scanning electron microscopy (SEM), neutron diffraction, positron annihilation spectroscopies, and ab initio calculations to investigate the evolution of the morphology and structure of α-MnO2 nanomaterials prepared via reduction of KMnO4 solution with C2H5OH prior to being annealed in air at 200-600 °C. We explored a novel evolution that α-MnO2 nucleation can be formed even at room temperature and gradually developed to α-MnO2 nanorods at above 500 °C. We also found the existence of H+ or K+ ions in the [1 × 1] tunnels of α-MnO2 and observed the simultaneous presence of Mn and O vacancies in α-MnO2 crystals at low temperatures. Increasing the temperature removed these O vacancies, leaving only the Mn vacancies in the samples. |
BibTeX:
@article{Dinh2022,
author = {Dinh, Van-Phuc and Luu, Tuyen Anh and Siemek, Krzysztof and Kozlenko, Denis P. and Le, Khiem Hong and Dang, Ngoc Toan and Nguyen, Tiep Van and Le Phuc, Nguyen and Tran, Tap Duy and Phan, Phuc T. and Lo, Son T. and Hoang, Kiet Anh Tuan and Dinh, Thanh Khan and Luong, Ngoc Thuy and Le, Ngoc Chung and Nguyen, Ngoc-Tuan and Ho, Thien-Hoang and Tran, Xuan Dong and Tran, Phong D. and Nguyen, Hung Q.},
title = {Crystallization Pathways and Evolution of Morphologies and Structural Defects of α-MnO 2 under Air Annealing},
journal = {Langmuir},
year = {2022},
volume = {38},
number = {50},
pages = {15604--15613},
url = {https://pubs.acs.org/doi/10.1021/acs.langmuir.2c02237},
doi = {10.1021/acs.langmuir.2c02237}
}
|
| Frank CE, McCabe EE, Orlandi F, Manuel P, Tan X, Deng Z, Jin C, Croft M, Emge T, Yu S, Wang H, Gopalan V, Lapidus S, Wu MX, Li MR, Gross J, Burger P, Mielewczyk-Gryń A, Klimczuk T, Xie W, Walker D and Greenblatt M (2022), "Fe3-xInSnxO6(x = 0, 0.25, or 0.5): A Family of Corundum Derivatives with Sn-Induced Polarization and Above Room Temperature Antiferromagnetic Ordering", Chem. Mater., Jun, 2022. Vol. 34(11), pp. 5020-5029. |
| Abstract: Three new double corundum derivative compounds, Fe3-xInSnxO6 (x = 0. 0.25, or 0.5), were synthesized at high pressure and temperature (6 GPa and 1400-1450 °C). All of the compounds order antiferromagnetically well above room temperature (TN = 608, 532, and 432 K for x = 0, 0.25, and 0.5, respectively). The x = 0 phase crystallizes as centrosymmetric R3¯ c, but the inclusion of closed-shell d10 Sn4+ induces x = 0.25 and 0.5 to crystallize as noncentrosymmetric R3c. Microprobe measurements indicate that for x = 0.25 and 0.5, the substitution of Sn4+ is not offset by vacancies, which implies the presence of Fe2+, as corroborated by X-ray absorption near-edge spectroscopy and single-crystal X-ray structure refinements. Neutron powder diffraction experiments on x = 0.5 indicate that these compounds are canted A-type antiferromagnets that, like Fe2O3 and InFeO3, consist of ferromagnetic layers that stack antiferromagnetically with a single magnetic transition. Weak ferromagnetic interactions persist to very high temperatures. Temperature-dependent second harmonic generation (SHG) measurements on x = 0.25 and 0.5 show a SHG response with ferroelectric-like hysteretic maxima that correspond with the respective magnetic transitions, which suggest coupling of the magnetic and polarization order. These new compounds provide more information about fine-tuning the electronic, magnetic, and structural properties of corundum-derived mutlferroics in the search for tunable high-temperature magnetoelectric materials. |
BibTeX:
@article{Frank2022,
author = {Frank, Corey E. and McCabe, Emma E. and Orlandi, Fabio and Manuel, Pascal and Tan, Xiaoyan and Deng, Zheng and Jin, Changqing and Croft, Mark and Emge, Thomas and Yu, Shukai and Wang, Huaiyu and Gopalan, Venkatraman and Lapidus, Saul and Wu, Mei Xia and Li, Man Rong and Gross, Juliane and Burger, Paul and Mielewczyk-Gryń, Aleksandra and Klimczuk, Tomasz and Xie, Weiwei and Walker, David and Greenblatt, Martha},
title = {Fe3-xInSnxO6(x = 0, 0.25, or 0.5): A Family of Corundum Derivatives with Sn-Induced Polarization and Above Room Temperature Antiferromagnetic Ordering},
journal = {Chem. Mater.},
year = {2022},
volume = {34},
number = {11},
pages = {5020--5029},
url = {https://pubs.acs.org/doi/10.1021/acs.chemmater.2c00312},
doi = {10.1021/acs.chemmater.2c00312}
}
|
| Ghosh K, Murshed MM, Frederichs T, Muniraju NK and Gesing TM (2022), "Structural, vibrational, thermal, and magnetic properties of mullite-type NdMnTiO5 ceramic", J. Am. Ceram. Soc., Apr, 2022. Vol. 105(4), pp. 2702-2712. |
| Abstract: Mullite-type RMn2O5 (R = Y, rare-earth element) ceramics are of ongoing research attention because of their interesting crystal-chemical and magnetic properties. We report nuclear and magnetic structures of NdMnTiO5 together with its spectroscopic, thermogravimetric, and magnetic properties. The polycrystalline sample is prepared by solid-state synthesis and characterized from neutron and X-ray powder diffraction data Rietveld refinements. NdMnTiO5 crystallizes in the orthorhombic space group Pbam with metric parameter a = 755.20(1) pm, b = 869.91(1) pm, c = 582.42(1) pm, and V = 382.62(1) 106 pm3. The Mn3+ and Ti4+ cations are observed to be located in the octahedral and pyramidal sites, respectively. The vibrational features in these polyhedral sites are characterized by Raman and Fourier transform infrared spectroscopes. The higher decomposition temperature of NdMnTiO5, compared to other RMn2O5 phases, is explained in terms of the higher bond strength of Ti-O bonds than those of Mn-O bonds. Temperature-dependent DC magnetic susceptibility suggests a paramagnetic to antiferromagnetic phase transition at 43(1) K. Inverse susceptibility in the paramagnetic region above 120 K follows the Curie-Weiss law, resulting in a magnetic moment of 6.33(1) μB per formula unit. Neutron diffraction data collected at 7.5 K reveal that the magnetic moments of Nd3+ and Mn3+ in NdMnTiO5 are incommensurately ordered with a propagation vector k = (0, 0.238, 0.117). |
BibTeX:
@article{Ghosh2022,
author = {Ghosh, Kowsik and Murshed, M. Mangir and Frederichs, Thomas and Muniraju, Naveen K.C. and Gesing, Thorsten M.},
title = {Structural, vibrational, thermal, and magnetic properties of mullite-type NdMnTiO5 ceramic},
journal = {J. Am. Ceram. Soc.},
year = {2022},
volume = {105},
number = {4},
pages = {2702--2712},
url = {https://onlinelibrary.wiley.com/doi/10.1111/jace.18261},
doi = {10.1111/jace.18261}
}
|
| Kademane AB, Bhandari C, Paudyal D, Cottrell S, Das P, Liu Y, Yiu Y, Kumar CM, Siemensmeyer K, Hoser A, Quintero-Castro DL, Vaknin D and Toft-Petersen R (2022), "Magnetization reversal driven by electron localization-delocalization crossover in the inverse spinel Co2VO4", Phys. Rev. B., Mar, 2022. Vol. 105(9), pp. 094408. |
| Abstract: Neutron diffraction, magnetization, and muon spin relaxation measurements, supplemented by density functional theory (DFT) calculations are employed to unravel temperature-driven magnetization reversal in inverse spinel Co2VO4. All measurements show a second-order magnetic phase transition at TC=168K to a collinear ferrimagnetic phase. Neutron diffraction measurements reveal two antiparallel ferromagnetic (FM) sublattices, belonging to magnetic ions on two distinct crystal lattice sites, where the relative balance between the two sublattices determine the net FM moment in the unit cell. As the evolution of the ordered moment with temperature differs between the two sublattices, the net magnetic moment reaches a maximum at TNC=138K and reverses its sign at TMR=65K. The DFT results suggest that the underlying microscopic mechanism for the reversal is a delocalization of the unfilled 3d-shell electrons on one sublattice just below TC, followed by a gradual localization as the temperature is lowered. This delocalized-localized crossover is supported by muon spectroscopy results, as strong T1 relaxation observed below TC indicates fluctuating internal fields. |
BibTeX:
@article{Kademane2022,
author = {Kademane, Abhijit Bhat and Bhandari, Churna and Paudyal, Durga and Cottrell, Stephen and Das, Pinaki and Liu, Yong and Yiu, Yuen and Kumar, C. M.Naveen and Siemensmeyer, Konrad and Hoser, Andreas and Quintero-Castro, Diana Lucia and Vaknin, David and Toft-Petersen, Rasmus},
title = {Magnetization reversal driven by electron localization-delocalization crossover in the inverse spinel Co2VO4},
journal = {Phys. Rev. B},
year = {2022},
volume = {105},
number = {9},
pages = {094408},
url = {https://link.aps.org/doi/10.1103/PhysRevB.105.094408},
doi = {10.1103/PhysRevB.105.094408}
}
|
| Kuzovnikov MA, Antonov VE, Hansen T, Ivanov AS, Kolesnikov AI, Kulakov VI, Muzalevsky VD, Savvin S and Tkacz M (2022), "Isotopic dependence of the frequency of optical vibrations in molybdenum monohydride", J. Alloys Compd., Feb, 2022. Vol. 893, pp. 162299. |
| Abstract: It is currently known that three hydrides – PdHx, MoHx, and TiHx – exhibit an inverse isotope effect in superconductivity. Namely, the phase with a heavier hydrogen isotope, deuterium, has a higher critical temperature. Hydrides and deuterides of palladium have intensively been studied both experimentally and theoretically, but the origin of the isotope effect has not been established with certainty. The commonly accepted explanation is that the effect is likely to be due to the strong anharmonicity of the optical hydrogen vibrations, which was considered to be responsible for the large deviation of the ratio of the fundamental optical frequencies ωH/ωD = 1.51 from the harmonic value 2 ≈ 1.41. In the present paper, powder samples of MoH1.1(1) and MoD1.07(3) were synthesized under a hydrogen / deuterium pressure of several gigapascals and studied by inelastic neutron scattering (INS) at ambient pressure and T = 10 K. The INS study demonstrated that optical vibrations of H atoms in MoH1.1 and D atoms in MoD1.07 are harmonic and the ratio of fundamental optical frequencies ωH/ωD = 1.44 is close to the harmonic value 2 ≈ 1.41. This shows that anharmonicity is not a necessary condition for the presence of the inverse isotope effect. The MoD1.07 sample was additionally studied by neutron diffraction (ND) at ambient pressure and T = 100 K. In agreement with previous ND results for MoH1.2, the ND study of MoD1.07 showed that deuterium atoms occupied almost all octahedral interstitial sites in its hexagonal close-packed metal lattice and formed a NiAs-type crystal structure with the composition close to MoD. The overstoichiometric composition MoD1.07 of the deuteride is likely to result from a small fraction D/Mo ∼ 0.07 of deuterium atoms partially occupying the tetrahedral interstices. |
BibTeX:
@article{Kuzovnikov2022,
author = {Kuzovnikov, Mikhail A. and Antonov, Vladimir E. and Hansen, Thomas and Ivanov, Alexandre S. and Kolesnikov, Alexander I. and Kulakov, Valery I. and Muzalevsky, Vitaly D. and Savvin, Stanislav and Tkacz, Marek},
title = {Isotopic dependence of the frequency of optical vibrations in molybdenum monohydride},
journal = {J. Alloys Compd.},
year = {2022},
volume = {893},
pages = {162299},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838821037099},
doi = {10.1016/j.jallcom.2021.162299}
}
|
| Marín-Villa P, Arauzo A, Drużbicki K and Fernandez-Alonso F (2022), "Unraveling the Ordered Phase of the Quintessential Hybrid Perovskite MAPbI3Thermophysics to the Rescue", J. Phys. Chem. Lett.. Vol. 13(36), pp. 8422-8428. |
| Abstract: Hybrid perovskites continue to attract an enormous amount of attention, yet a robust microscopic picture of their different phases as well as the extent and nature of the disorder present remains elusive. Using specific-heat data along with high-resolution inelastic neutron scattering and ab initio modeling, we address this ongoing challenge for the case of the ordered phase of the quintessential hybrid-perovskite MAPbI3. At low temperatures, the specific heat of MAPbI3 reveals strong deviations from the Debye limit, a common feature of pure hybrid perovskites and their mixtures. Our thermophysical analysis demonstrates that the (otherwise ordered) structure around the organic moiety is characterized by a substantial lowering of the local symmetry relative to what can be inferred from crystallographic studies. The physical origin of the observed thermophysical anomalies is unequivocally linked to excitations of sub-terahertz optical phonons responsible for translational-librational distortions of the octahedral units. |
BibTeX:
@article{Marin-Villa2022,
author = {Marín-Villa, Pelayo and Arauzo, Ana and Drużbicki, Kacper and Fernandez-Alonso, Felix},
title = {Unraveling the Ordered Phase of the Quintessential Hybrid Perovskite MAPbI3Thermophysics to the Rescue},
journal = {J. Phys. Chem. Lett.},
year = {2022},
volume = {13},
number = {36},
pages = {8422--8428},
doi = {10.1021/acs.jpclett.2c02208}
}
|
| Młynarek-Żak K, Pakieła W, Łukowiec D, Bajorek A, Gębara P, Szakál A, Dhiman I and Babilas R (2022), "Structure and selected properties of Al–Cr–Fe alloys with the presence of structurally complex alloy phases", Sci. Rep., Aug, 2022. Vol. 12(1), pp. 14194. |
| Abstract: The aim of the study was to supplement the data on the Al 65 Cr 20 Fe 15 alloy with binary phase structure and the Al 71 Cr 24 Fe 5 alloy with multiphase structure prepared with two different cooling rates from the liquid state. The presence of the structurally complex Al 65 Cr 27 Fe 8 phase was confirmed by neutron diffraction, scanning electron microscopy with the analysis of chemical composition and transmission electron microscopy. Additionally, the Al 8 Cr 5 phase with γ-brass structure was identified for Al 71 Cr 24 Fe 5 alloy in both cooling rates from the liquid state. Due to the interesting features of structurally complex alloys, the wear resistance, magnetic properties, and corrosion products after performing electrochemical tests were examined. Based on pin-on-disc measurements, a lower friction coefficient was observed for the Al 65 Cr 20 Fe 15 alloy (µ ≈ 0.55) compared to the Al 71 Cr 24 Fe 5 multiphase alloy (µ ≈ 0.6). The average hardness of the binary phase Al 65 Cr 20 Fe 5 alloy (HV 0.1 = 917 ± 30) was higher compared to the multiphase Al 71 Cr 24 Fe 5 alloy (HV 0.1 = 728 ± 34) and the single phase Al–Cr–Fe alloys described in the literature. Moreover, the beneficial effect of rapid solidification on hardness was demonstrated. The alloys Al 65 Cr 20 Fe 15 and Al 71 Cr 24 Fe 5 showed paramagnetic behavior, however rapidly solidified Al 71 Cr 24 Fe 5 alloy indicated an increase of magnetic properties. The studied alloys were characterized by the presence of passive layers after electrochemical tests. A higher amount of oxides on the surface of the Al 71 Cr 24 Fe 5 alloy was recorded due to the positive effect of chromium on the stabilization of the passive layer. |
BibTeX:
@article{Mynarek-Zak2022,
author = {Młynarek-Żak, K. and Pakieła, W. and Łukowiec, D. and Bajorek, A. and Gębara, P. and Szakál, A. and Dhiman, I. and Babilas, R.},
title = {Structure and selected properties of Al–Cr–Fe alloys with the presence of structurally complex alloy phases},
journal = {Sci. Rep.},
year = {2022},
volume = {12},
number = {1},
pages = {14194},
url = {https://www.nature.com/articles/s41598-022-17870-0},
doi = {10.1038/s41598-022-17870-0}
}
|
| Naseer K, Sathiyapriya G, Marimuthu K, Piotrowski T, Alqahtani MS and Yousef ES (2022), "Optical, elastic, and neutron shielding studies of Nb2O5 varied Dy3+ doped barium-borate glasses", Optik (Stuttg)., Feb, 2022. Vol. 251, pp. 168436. |
| Abstract: A sequence of modifier oxide (Nb2O5) varied Dy3+ doped barium-borate glasses have been manufactured. Various structural and optical characterizations are done. Investigation of the local symmetry around the Dy3+ in the host medium is predicted through the bonding parameter analysis and Judd-Ofelt intensity parameters determined by employing the least-squares fitting method. Various radiative properties for the emission transitions 4F9/2→6H15/2, 4F9/2→6H13/2, and 4F9/2→6H11/2 of the Dy3+ are estimated. Further, the Y/B ratio intensity ratio values, CIE color coordinates, color purity, and color-correlated temperature of the prepared glasses were calculated using the luminescence spectra. Based on the spectroscopic quality factor and CIE coordinates, the prepared glasses expose their aptness for the laser media and white-light-emitting devices. Neutron shielding efficiency is evaluated by the computation of fast neutron effective removal cross-section and neutron scattering, absorption, and total macroscopic cross-sections. It was found that modification by Nb2O5 makes an enhancement mainly in fast neutron-shielding competence, but it also has some minor influence on thermal neutron absorption efficiency. |
BibTeX:
@article{Naseer2022,
author = {Naseer, K.A. and Sathiyapriya, G. and Marimuthu, K. and Piotrowski, Tomasz and Alqahtani, Mohammed S. and Yousef, El Sayed},
title = {Optical, elastic, and neutron shielding studies of Nb2O5 varied Dy3+ doped barium-borate glasses},
journal = {Optik (Stuttg).},
year = {2022},
volume = {251},
pages = {168436},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0030402621019409},
doi = {10.1016/j.ijleo.2021.168436}
}
|
| Orzechowska M, Rećko K, Soloviov D, Klekotka U, Biernacka M, Satuła D, Olszewski W, Kalska-Szostko B, Beskrovnyy A and Szymański K (2022), "Selected properties of surface modified GaxFe3-xO4 with 0≤x≤1.5", Phase Transitions., Feb, 2022. Vol. 96(2), pp. 97-104. |
| Abstract: The influence of the surface modification on the magnetism of 4–14 nm sized core and core/shell gallium ferrites obtained by different preparation methods (Massart's and thermal decomposition from acetylacetonates) was studied. The physical properties of GaxFe3-xO4 were investigated in a wide range of Ga admixtures 0 ≤ x ≤ 1.5. Ga ions location at 8a or/and 16d positions of a spinel structure depends on the synthesis method and has a pronounced effect on the superparamagnetic properties of nanoparticles. Magnetization and Mössbauer experiments show the dominant superparamagnetic contribution for the nanoparticles with x > 0.8 with the blocking temperature TB significantly below 200 K. Surface-modified nanoferrites disclosed spontaneous magnetization that does not exceed 60 emu/g. |
BibTeX:
@article{Orzechowska2023,
author = {Orzechowska, M. and Rećko, K. and Soloviov, D. and Klekotka, U. and Biernacka, M. and Satuła, D. and Olszewski, W. and Kalska-Szostko, B. and Beskrovnyy, A. and Szymański, K.},
title = {Selected properties of surface modified GaxFe3-xO4 with 0≤x≤1.5},
journal = {Phase Transitions},
year = {2022},
volume = {96},
number = {2},
pages = {97--104},
url = {https://www.tandfonline.com/doi/full/10.1080/01411594.2022.2159406},
doi = {10.1080/01411594.2022.2159406}
}
|
| Osiecka-Drewniak N, Juszyńska-Gałązka E, Zając W and Chudoba D (2022), "Vibrational dynamics of ethosuximide polymorphs. Infrared absorption and inelastic neutron scattering spectroscopy and model calculations", Spectrochim. Acta Part A Mol. Biomol. Spectrosc., Oct, 2022. Vol. 279, pp. 121468. |
| Abstract: Commercially available and administered to the patients ethosuximide is a racemic mixture of two enantiomers, each of them exist in different conformations. The presence of the species mentioned are proven by the title experimental methods aided by DFT model calculations. Results of the latter are matched against spectroscopic data by the clustering window analysis. One type of hydrogen bonds exist in the solid forms of ethosuximide NH⋯O, leading to the polymorphic variety of the substance studied. |
BibTeX:
@article{Osiecka-Drewniak2022,
author = {Osiecka-Drewniak, Natalia and Juszyńska-Gałazka, Ewa and Zajac, Wojciech and Chudoba, Dorota},
title = {Vibrational dynamics of ethosuximide polymorphs. Infrared absorption and inelastic neutron scattering spectroscopy and model calculations},
journal = {Spectrochim. Acta Part A Mol. Biomol. Spectrosc.},
year = {2022},
volume = {279},
pages = {121468},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1386142522006175},
doi = {10.1016/j.saa.2022.121468}
}
|
| Pajerowski DM, Podlesnyak AP, Herbrych J and Manson J (2022), "High-pressure inelastic neutron scattering study of the anisotropic S=1 spin chain [Ni(HF2)(3-Clpyradine)4]BF4", Phys. Rev. B., Apr, 2022. Vol. 105(13), pp. 134420. |
| Abstract: [Ni(HF2)(3-Clpyradine)4]BF4 (NBCT) is a one-dimensional, S=1 spin-chain material that shows no long-range magnetic order down to thermometer temperatures of 0.1 K. Previous ambient pressure inelastic neutron scattering experiments identified NBCT to be in the large-D quantum paramagnetic phase of the D/J phase diagram, where D is the axial single-ion anisotropy and J is the intrachain superexchange. Here, we extend the previous experiments to a hydrostatic pressure of 0.9 GPa. By comparing to density matrix renormalization group calculations, we find D/J increases from 1.5 to 3.2 as pressure increases from 0 GPa to 0.9 GPa, which pushes the system further into the large-D phase. |
BibTeX:
@article{Pajerowski2022,
author = {Pajerowski, Daniel M. and Podlesnyak, Andrey P. and Herbrych, Jacek and Manson, Jamie},
title = {High-pressure inelastic neutron scattering study of the anisotropic S=1 spin chain [Ni(HF2)(3-Clpyradine)4] B F4},
journal = {Phys. Rev. B},
year = {2022},
volume = {105},
number = {13},
pages = {134420},
url = {https://link.aps.org/doi/10.1103/PhysRevB.105.134420},
doi = {10.1103/PhysRevB.105.134420}
}
|
| Pajor K, Rutkowski B, Gondek Ł, Błyskun P, Reehuis M, Wieczerzak K and Kozieł T (2022), "The Scavenging Effect of Different Rare-Earth Elements in the Low-Purity Zr50Cu40Al10 Alloy", Metall. Mater. Trans. A., Aug, 2022. Vol. 53(8), pp. 2902-2925. |
| Abstract: Glass-forming alloys are very sensitive to oxygen contaminations. Here, the oxygen-scavenging effect of five rare-earth elements (REEs) was studied when added to the Zr50Cu40Al10 alloy, synthesized from commercially available zirconium. The effects of precise REEs additions (Y, Sc, Lu, Gd, Nd) with respect to the measured oxygen content, based on the stoichiometric relationship in the M2O3 oxide, are reported. Additionally, the influence of double and triple REE-to-oxygen ratios on the critical diameter (Dc) and other glass-forming ability (GFA) indicators were investigated. To evaluate the GFA and phase transformations during heating, differential thermal analysis was performed along with neutron diffraction. The combination of these two techniques allowed to identify crystallization products and distinguish the differences in phase transformations of low and high-oxygen-content alloys. Microstructural analysis was carried out by means of electron microscopy (SEM, STEM), supported by X-ray diffraction. The best oxygen scavengers were found to be rare earths that form cubic sesquioxides, i.e., Y, Sc, and Lu, allowing to increase Dc in the high-oxygen Zr50Cu40Al10 alloy from 2.5 mm up to 8 mm (double-stoichiometric concentration of Y-to-oxygen). Our results indicate that low-purity alloys can be easily vitrified, highlighting their potential for wide commercialization.[Figure not available: see fulltext.] |
BibTeX:
@article{Pajor2022,
author = {Pajor, Krzysztof and Rutkowski, Bogdan and Gondek, Łukasz and Błyskun, Piotr and Reehuis, Manfred and Wieczerzak, Krzysztof and Kozieł, Tomasz},
title = {The Scavenging Effect of Different Rare-Earth Elements in the Low-Purity Zr50Cu40Al10 Alloy},
journal = {Metall. Mater. Trans. A},
year = {2022},
volume = {53},
number = {8},
pages = {2902--2925},
url = {https://link.springer.com/10.1007/s11661-022-06714-1},
doi = {10.1007/s11661-022-06714-1}
}
|
| Pan C, Zhao G, Li S, Wang X, Wang J, Tao M, Zhang X, Yang C, Xu J, Yin W, Yin L, Song W, Tong P, Zhu X, Yang J and Sun Y (2022), "Superior piezoelectricity and resistivity in CaBi2Nb2O9 high-temperature piezoelectric ceramics: synergy of structural distortion and weak texturing", J. Mater. Chem. C. Vol. 10(42), pp. 15851-15860. |
| Abstract: The polycrystalline CaBi 2 Nb 2 O 9 ceramics with the addition of B 2 O 3 can realize a large d 33 of 20.4 pC N −1 and an ultra-high electrical resistivity of 1.4 × 10 7 Ω cm (at 600 °C), while still retaining a high T C of 958 °C. |
BibTeX:
@article{Pan2022,
author = {Pan, Chengbing and Zhao, Gaochao and Li, Sumei and Wang, Xuelian and Wang, Jiamingzhu and Tao, Ming and Zhang, Xuekai and Yang, Cheng and Xu, Juping and Yin, Wen and Yin, Lihua and Song, Wenhai and Tong, Peng and Zhu, Xuebin and Yang, Jie and Sun, Yuping},
title = {Superior piezoelectricity and resistivity in CaBi2Nb2O9 high-temperature piezoelectric ceramics: synergy of structural distortion and weak texturing},
journal = {J. Mater. Chem. C},
year = {2022},
volume = {10},
number = {42},
pages = {15851--15860},
url = {http://xlink.rsc.org/?DOI=D2TC03598G},
doi = {10.1039/D2TC03598G}
}
|
| Papagiannopoulos A, Sentoukas T, Pispas S, Radulescu A, Pipich V and Lang C (2022), "Length-scale dependence of pH- and temperature-response of PDMAEMA-b-PHPMA block copolymer self-assemblies in aqueous solutions", Polymer (Guildf)., Jan, 2022. Vol. 239, pp. 124428. |
| Abstract: Amphiphilic doubly responsive block copolymers poly(2-(dimethylamino)ethyl methacrylate)-b-poly(hydroxy propyl methacrylate) (PDMAEMA-b-PHPMA) were studied by very small angle and small angle neutron scattering (VS/SANS) in aqueous solutions. A multi-level hierarchical approach was used to fit the experimental data and Bayesian analysis was performed to explore possible interdependencies between the extracted parameters. Hydrophobic contacts between the block copolymer monomers appear to create local concentration inhomogeneities (2–4 nm) whose size and mass depends on the preparation protocol. A solvent-exchange solubilization protocol leads to smaller inhomogeneities in comparison to a direct solubilization protocol due to better arrangement of the PHPMA hydrophobic units. At acidic and neutral pH hierarchical structure is observed where the local inhomogeneities are organized within aggregates (∼200 nm) and grow or shrink with temperature depending on pH. At acidic pH aggregates are interconnected into large clusters. By increasing temperature, aggregates become larger in both afcidic and neutral pH, while this response is stronger for the solvent-exchange solubilization protocol. Very interestingly, aggregates transform into self-similar superstructures at basic pH (where PDMAEMA is uncharged) to an extend that it is strongly preparation protocol-dependent. These transitions at length scales from 1 to 1000 nm open many possibilities for advanced multiple stimuli-responsive loading and release of proteins and drug molecules in such polymeric nanostructures. |
BibTeX:
@article{Papagiannopoulos2022,
author = {Papagiannopoulos, Aristeidis and Sentoukas, Theodore and Pispas, Stergios and Radulescu, Aurel and Pipich, Vitali and Lang, Christian},
title = {Length-scale dependence of pH- and temperature-response of PDMAEMA-b-PHPMA block copolymer self-assemblies in aqueous solutions},
journal = {Polymer (Guildf).},
year = {2022},
volume = {239},
pages = {124428},
url = {https://linkinghub.elsevier.com/retrieve/pii/S003238612101051X},
doi = {10.1016/j.polymer.2021.124428}
}
|
| Pomjakushin V, Perez-Mato JM, Fischer P, Keller L and Sikora W (2022), "Revisiting the antiferromagnetic structure of Tb14Ag51: the importance of distinguishing alternative symmetries for a multidimensional order parameter", Acta Crystallogr. Sect. B Struct. Sci. Cryst. Eng. Mater., Apr, 2022. Vol. 78(2), pp. 172-178. |
| Abstract: The antiferromagnetic structure of Tb 14 Ag 51 with the propagation vector [1/3, 1/3, 0] and the parent space group P 6/ m is revisited using both magnetic symmetry and irreducible representation arguments. A new magnetic structure under the hexagonal Shubnikov magnetic space group P 6 ′ which fits much better the experimental data is found. This new solution was obtained by constraining the spin arrangement to one of the three possible magnetic space groups of maximal symmetry that can be realized by a magnetic ordering transforming according to the four-dimensional physically irreducible representation that is known to be relevant in this magnetic phase. The refined model, parameterized under P 6 ′, implicitly includes the presence of a third harmonic with the propagation vector at the gamma point [0, 0, 0], which has an important weight in the final result. The structure consists of 13 symmetry-independent Tb magnetic moments with the same size of 8.48 (2) μ B , propagating cycloidally in the ab plane. The modulation has a substantial deviation from being purely sinusoidal due to the contribution of the mentioned third harmonic. |
BibTeX:
@article{Pomjakushin2022,
author = {Pomjakushin, Vladimir and Perez-Mato, Juan Manuel and Fischer, Peter and Keller, Lukas and Sikora, Wieslawa},
title = {Revisiting the antiferromagnetic structure of Tb14Ag51: the importance of distinguishing alternative symmetries for a multidimensional order parameter},
journal = {Acta Crystallogr. Sect. B Struct. Sci. Cryst. Eng. Mater.},
year = {2022},
volume = {78},
number = {2},
pages = {172--178},
url = {https://scripts.iucr.org/cgi-bin/paper?S205252062200124X},
doi = {10.1107/S205252062200124X}
}
|
| Rajput S, Balasubramanian P, Singh A, Damay F, Kumar CM, Tabis W, Maitra T and Malik VK (2022), "Coexisting magnetic structures and spin reorientation in Er0.5Dy0.5FeO3: Bulk magnetization, neutron scattering, specific heat, and density functional theory studies", Phys. Rev. B., Jun, 2022. Vol. 105(21), pp. 214436. |
| Abstract: The complex magnetic structures, spin reorientation, and associated exchange interactions have been investigated in Er0.5Dy0.5FeO3 using bulk magnetization, neutron diffraction, specific heat measurements, and density functional theory calculations. The Fe3+ spins order as G-type antiferromagnet structure depicted by Γ4(Gx, Ay, Fz) irreducible representation below 700 K, similar to its end compounds. The bulk magnetization data indicate occurrence of the spin-reorientation and rare-earth magnetic moments' polarization below ∼75 K and 10 K, respectively. The neutron diffraction studies confirm an "incomplete"Γ4→ Γ2(Fx, Cy, Gz) spin-reorientation initiated ≤75 K. Although the relative volume fraction of the two magnetic structures varies with decreasing temperature, both coexist even at 1.5 K. Below 10 K, the polarization of Er3+/Dy3+ moments in a cyR arrangement develops, which gradually increases with decreasing temperature. At 2 K, magnetic structure associated with czR arrangement of Er3+/Dy3+ moments also appears. At 1.5 K, while the rare-earth magnetic moments show a cyR+czR-type arrangement, the Fe3+ spins are represented by a combination of a Γ2+Γ4 (Gz,Gx) arrangement. A clear signature of the magnetic structure with Γ1(Gy) representation, symmetrically compatible with the czR-type arrangement of rare-earth moments, is not confirmed from the refinement of the neutron diffraction data. The observed Schottky anomaly at 2.5 K suggests that the "rare-earth ordering"is induced by polarization due to Fe3+ spins. The Er3+-Fe3+ and Er3+-Dy3+ exchange interactions, obtained from first principle calculations, indicate that these interactions primarily cause the complicated spin reorientation and cyR rare-earth ordering in the system, respectively, while the dipolar interactions between rare-earth moments result in the czR type rare-earth ordering at 2 K. |
BibTeX:
@article{Rajput2022,
author = {Rajput, Sarita and Balasubramanian, Padmanabhan and Singh, Ankita and Damay, Françoise and Kumar, C. M.N. and Tabis, W. and Maitra, T. and Malik, V. K.},
title = {Coexisting magnetic structures and spin reorientation in Er0.5 Dy0.5 FeO3: Bulk magnetization, neutron scattering, specific heat, and density functional theory studies},
journal = {Phys. Rev. B},
year = {2022},
volume = {105},
number = {21},
pages = {214436},
url = {https://link.aps.org/doi/10.1103/PhysRevB.105.214436},
doi = {10.1103/PhysRevB.105.214436}
}
|
| Rećko K, Orzechowska M, Olszewski W, Beskrovnyy A, Biernacka M, Klekotka U, Miaskowski A and Szymański K (2022), "Investigations on the enhancement of thermomagnetic properties in Fe2.4Ga0.6O4", Phase Transitions., Feb, 2022. Vol. 96(2), pp. 105-114. |
| Abstract: The structural, magnetic and calorimetric properties of Fe2.4Ga0.6O4 nanoferrite have been investigated. X-ray and neutron diffraction coupled analyses using Rietveld refinements have shown that the samples under investigation, obtained by different bottom-up methods, crystalize with a cubic structure in the (Formula presented.) space group (N° 227). The Ga3+ ions preferentially occupying the tetrahedral sublattice of the inverse spinel partly screen the dipole–dipole interactions and lead to the reduction of the magnetic response of Fe3+ ones. Calorimetric measurements confirm that the nanosized Fe2.4Ga0.6O4 system weakly agglomerates and simultaneously collect and release optimal amount of heat under the influence of an alternating magnetic field with the 15.3 kA/m of maximum magnetic field strength and 532 kHz of frequency. The values of the specific absorption coefficients obtained for gallium ferrites, similar to those typical for cobalt ferrites used commercially in biomedicine, together with very low superparamagnetic blocking temperature validated by Mössbauer spectroscopy analysis, make the system an attractive therapeutic material. |
BibTeX:
@article{Recko2023,
author = {Rećko, K. and Orzechowska, M. and Olszewski, W. and Beskrovnyy, A. and Biernacka, M. and Klekotka, U. and Miaskowski, A. and Szymański, K.},
title = {Investigations on the enhancement of thermomagnetic properties in Fe2.4Ga0.6O4},
journal = {Phase Transitions},
year = {2022},
volume = {96},
number = {2},
pages = {105--114},
url = {https://www.tandfonline.com/doi/full/10.1080/01411594.2022.2159404},
doi = {10.1080/01411594.2022.2159404}
}
|
| Szyba D, Bajorek A, Babilas D, Temleitner L, Łukowiec D and Babilas R (2022), "New resorbable Ca-Mg-Zn-Yb-B-Au alloys: Structural and corrosion resistance characterization", Mater. Des., Jan, 2022. Vol. 213, pp. 110327. |
| Abstract: New resorbable Ca32Mg12Zn38Yb18-2xBxAux (x = 1,2) alloys were designed and prepared in order to verify their use for medical applications as potential short-term implants. Their amorphous structure containing some crystalline phases (CaZn, CaZn2 and MgZn) was determined by X-ray and neutron diffraction and electron microscopy methods. The biocorrosion behavior of the plates was tested by hydrogen evolution measurements, immersion, electrochemical polarization tests, and electrochemical impedance spectroscopy in Ringer's solution at 37 °C. The corrosion analysis was also supplemented by X-ray diffraction, photoelectron, and ICP-AES spectroscopy. The corrosion resistivity measurements revealed that the alloys manifest enhanced corrosion resistance. The corrosion current density for Ca32Mg12Zn38Yb18-2xBxAux (x = 1, 2) alloys were 18.46 and 8.79 μA/cm2, which is lower than for pure Mg (47.85 μA/cm2) and Zn (33.96 μA/cm2). A decreasing tendency for hydrogen to evolve as a function of time was noted. The hydrogen evolution did not exceed 1 ml/cm2 over 1 h and average corrosion rate is calculated as 0.32 g/m2. h for Ca32Mg12Zn38Yb14B2Au2 alloy after 312 h. The corrosion mechanism of the alloys includes an anodic dissolution, a hydroxide precipitation, corrosion product layer formation and corrosion propagation stage. |
BibTeX:
@article{Szyba2022,
author = {Szyba, Dawid and Bajorek, Anna and Babilas, Dorota and Temleitner, László and Łukowiec, Dariusz and Babilas, Rafał},
title = {New resorbable Ca-Mg-Zn-Yb-B-Au alloys: Structural and corrosion resistance characterization},
journal = {Mater. Des.},
year = {2022},
volume = {213},
pages = {110327},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0264127521008820},
doi = {10.1016/j.matdes.2021.110327}
}
|
| Szytuła A, Penc B and Stec-Kuźniar E (2022), "Crystal Structure of Synthetic Feroxyhite δ-FeOOH Studied with Neutron Diffraction", Acta Phys. Pol. A. Vol. 142(2), pp. 306-308. |
| Abstract: The synthetic polycrystalline sample of δ-FeOOH was investigated by means of neutron diffraction. Based on these data, the parameters of the crystal structure are determined. This compound crystallizes in the hexagonal structure described by the space group P¯3m1, in which the oxygen O2- ions in the 2d site form the octahedral network. The Fe3+ ions randomly occupy the 1a (53%) and 1b (47%) sites, and the hydrogen atoms half-occupy two positions in the 2d site. The magnetic contribution to the neutron diffraction pattern is very small and does not give possibility to determine the magnetic structure. |
BibTeX:
@article{Szytua2022,
author = {Szytuła, A. and Penc, B. and Stec-Kuźniar, E.},
title = {Crystal Structure of Synthetic Feroxyhite δ-FeOOH Studied with Neutron Diffraction},
journal = {Acta Phys. Pol. A},
year = {2022},
volume = {142},
number = {2},
pages = {306--308},
doi = {10.12693/APhysPolA.142.306}
}
|
| Tang L, Jiang F, Wróbel J, Liu B, Kabra S, Duan R, Luan J, Jiao Z, Attallah M, Nguyen-Manh D, Nguyen-Manh D and Cai B (2022), "In situ neutron diffraction unravels deformation mechanisms of a strong and ductile FeCrNi medium entropy alloy", J. Mater. Sci. Technol.. Vol. 116, pp. 103-120. |
| Abstract: We investigated the mechanical and microstructural responses of a high-strength equal-molar medium entropy FeCrNi alloy at 293 and 15 K by in situ neutron diffraction testing. At 293 K, the alloy had a very high yield strength of 651 ± 12 MPa, with a total elongation of 48% ± 5%. At 15 K, the yield strength increased to 1092 ± 22 MPa, but the total elongation dropped to 18% ± 1%. Via analyzing the neutron diffraction data, we determined the lattice strain evolution, single-crystal elastic constants, stacking fault probability, and estimated stacking fault energy of the alloy at both temperatures, which are the critical parameters to feed into and compare against our first-principles calculations and dislocation-based slip system modeling. The density functional theory calculations show that the alloy tends to form short-range order at room temperatures. However, atom probe tomography and atomic-resolution transmission electron microscopy did not clearly identify the short-range order. Additionally, at 293 K, experimental measured single-crystal elastic constants did not agree with those determined by first-principles calculations with short-range order but agreed well with the values from the calculation with the disordered configuration at 2000 K. This suggests that the alloy is at a metastable state resulted from the fabrication methods. In view of the high yield strength of the alloy, we calculated the strengthening contribution to the yield strength from grain boundaries, dislocations, and lattice distortion. The lattice distortion contribution was based on the Varenne-Luque-Curtine strengthening theory for multi-component alloys, which was found to be 316 MPa at 293 K and increased to 629 MPa at 15 K, making a significant contribution to the high yield strength. Regarding plastic deformation, dislocation movement and multiplication were found to be the dominant hardening mechanism at both temperatures, whereas twinning and phase transformation were not prevalent. This is mainly due to the high stacking fault energy of the alloy as estimated to be 63 mJm−2 at 293 K and 47 mJm−2 at 15 K. This work highlights the significance of lattice distortion and dislocations played in this alloy, providing insights into the design of new multi-component alloys with superb mechanical performance for cryogenic applications. |
BibTeX:
@article{Tang2022,
author = {Tang, L. and Jiang, F.Q. and Wróbel, J.S. and Liu, B. and Kabra, S. and Duan, R.X. and Luan, J.H. and Jiao, Z.B. and Attallah, M.M. and Nguyen-Manh, D. and Nguyen-Manh, D. and Cai, B.},
title = {In situ neutron diffraction unravels deformation mechanisms of a strong and ductile FeCrNi medium entropy alloy},
journal = {J. Mater. Sci. Technol.},
year = {2022},
volume = {116},
pages = {103--120},
doi = {10.1016/j.jmst.2021.10.034}
}
|
| Tatarchuk T, Danyliuk N, Kotsyubynsky V, Shumskaya A, Kaniukov E, Ghfar AA, Naushad M and Shyichuk A (2022), "Eco-friendly synthesis of cobalt-zinc ferrites using quince extract for adsorption and catalytic applications: An approach towards environmental remediation", Chemosphere., May, 2022. Vol. 294, pp. 133565. |
| Abstract: Cobalt-zinc ferrite nanoparticles were synthesized using environmentally friendly approach with quince extract as a reducing agent. Crystal structure and morphology of the obtained materials were studied by XRD, SEM-EDS, Mössbauer and IR spectroscopy. The synthesized nanoparticles have a cubic spinel structure and crystallite size ranging from 5 to 9 nm. The infrared spectra contain characteristic absorption bands for the MA-O (∼560 cm−1) and MB-O bonds (∼420 cm−1). Force constants were calculated for both tetrahedral and octahedral bonds. As the Co content increases, the force constant for the tetrahedral bond increases and the force constant for the octahedral bond decreases. The obtained ferrite nanoparticles have good magnetization as shown by VSM (in the range from 36 to 67 emu/g). Magnetic nanoparticles CoxZn1-xFe2O4 were also tested for induction heating with electromagnetic field. The sample with x (Co) = 0.4 has the highest specific absorption rate. The synthesized samples were tested as adsorbents using the Congo Red dye as model pollutant. The best adsorbent was pure zinc ferrite with the adsorption capacity of 24.7 mg/g. The catalytic activity of the obtained ferrites for the decomposition of H2O2 was studied as well. The most active catalyst was pure cobalt ferrite. Probably, the active centers are octahedral cobalt ions. Thus, the obtained magnetic nanoparticles can be used for the adsorptive removal of pollutants, catalytic decomposition of the H2O2 and low-frequency hyperthermia. |
BibTeX:
@article{Tatarchuk2022,
author = {Tatarchuk, Tetiana and Danyliuk, Nazarii and Kotsyubynsky, Volodymyr and Shumskaya, Alena and Kaniukov, Egor and Ghfar, Ayman A. and Naushad, Mu. and Shyichuk, Alexander},
title = {Eco-friendly synthesis of cobalt-zinc ferrites using quince extract for adsorption and catalytic applications: An approach towards environmental remediation},
journal = {Chemosphere},
year = {2022},
volume = {294},
pages = {133565},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0045653522000546},
doi = {10.1016/j.chemosphere.2022.133565}
}
|
| Valkovskiy GA, Mistonov AA, Chudoba DM, Baranov DA, Hetmańczyk J, Hetmańczyk L, Shelyapina MG and Tsyganenko AA (2022), "Water in the crystal structure of NaBiO3-based phase: A spectroscopical insight", Mater. Chem. Phys., Jul, 2022. Vol. 286, pp. 126156. |
| Abstract: Water embedded in the crystal structure of a solid hydrate may affect the functional properties of the material. A decisive step towards understanding the role of water in the restricted geometry is to unravel the arrangement and dynamics of water molecules. The paper attacks this issue using the example of NaBiO3–based material containing at ambient conditions a mixture of dehydrated NaBiO3 and hydrated NaBiO3⋅nH2O phase, with the latter being predominant. Inelastic neutron scattering and infrared spectroscopy are applied to explore the vibrations of water molecules for the hydrated phase in the initial state and during the release of water upon heating that eventually leads to a complete transformation to the dehydrated phase. The major peaks in the infrared spectra were assigned, particularly with the help of deuteration. Dynamic interaction of structurally equivalent water molecules was revealed from the analysis of water bending modes in infrared and Raman spectra. The change in the conformation of water molecules is discussed, as well as the deformation of matrix bonds during sample dehydration. |
BibTeX:
@article{Valkovskiy2022,
author = {Valkovskiy, G. A. and Mistonov, A. A. and Chudoba, D. M. and Baranov, D. A. and Hetmanczyk, J. and Hetmanczyk, L. and Shelyapina, M. G. and Tsyganenko, A. A.},
title = {Water in the crystal structure of NaBiO3-based phase: A spectroscopical insight},
journal = {Mater. Chem. Phys.},
year = {2022},
volume = {286},
pages = {126156},
url = {https://linkinghub.elsevier.com/retrieve/pii/S025405842200462X},
doi = {10.1016/j.matchemphys.2022.126156}
}
|
| Vasilenko T, Кirillov А, Islamov A, Doroshkevich A, Łudzik K, Chudoba DM and Mita C (2022), "Permeability of a coal seam with respect to fractal features of pore space of fossil coals", Fuel., Dec, 2022. Vol. 329, pp. 125113. |
| Abstract: The results of calculations of permeability of coal beds by Kozeny-Carman model are reported. The applicability of the model is proven in the case of known total porosity and specific surface of pore volume of fossil coal that are measured by small-angle neutron scattering experiments. By means of the fractal theory, it is shown that when the depth of coal bed increases, the reduction of the fractal dimension results in enlarged volume of macropores that provide enhanced permeability and gas content of deep seated coal beds. |
BibTeX:
@article{Vasilenko2022,
author = {Vasilenko, Tatyana and Кirillov, Аndrey and Islamov, Akhmed and Doroshkevich, Alexander and Łudzik, Katarzyna and Chudoba, Dorota M. and Mita, Carmen},
title = {Permeability of a coal seam with respect to fractal features of pore space of fossil coals},
journal = {Fuel},
year = {2022},
volume = {329},
pages = {125113},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0016236122019548},
doi = {10.1016/j.fuel.2022.125113}
}
|
| Ways T, Filippov S, Maji S, Glassner M, Cegłowski M, Hoogenboom R, King S, Lau W and Khutoryanskiy V (2022), "Mucus-penetrating nanoparticles based on chitosan grafted with various non-ionic polymers: Synthesis, structural characterisation and diffusion studies", J. Colloid Interface Sci.. Vol. 626, pp. 251-264. |
| Abstract: Transmucosal administration offers numerous advantages for drug delivery as it usually helps to avoid first pass metabolism, provides rapid onset of action, and is a non-invasive route. Mucosal surfaces are covered by a viscoelastic mucus gel layer which acts as a protective barrier preventing the entrance of harmful substances into the human tissues. This function of mucus also inhibits the diffusion of drugs and nano-formulations and can result in a significant reduction of their efficacy. The design of mucus-penetrating nanoparticles can overcome the barrier function of mucus which may lead to better therapeutic outcomes. In this study, chitosan was chemically modified by grafting short chains of poly(ethylene glycol), poly(2-hydroxyethyl acrylate), poly(2-ethyl-2-oxazoline), or poly(N-vinyl pyrrolidone) and the resulting chitosan derivatives were used to prepare nanoparticles using an ionic gelation method with sodium tripolyphosphate. These nanoparticles were characterised using dynamic light scattering, transmission electron microscopy, small-angle neutron scattering and nanoparticle tracking analysis. Small-angle neutron scattering data revealed the presence of a large amount of water inside these nanoparticles and lack of a heterogeneous internal structure. The nanogel model with low crosslinking density is suggested as the most feasible model to describe the structure of these nanoparticles. The studies of the behaviour of these nanoparticles in bovine submaxillary mucin solutions and their penetration into sheep nasal mucosa indicated greater diffusivity of modified chitosan nanoparticles compared to unmodified chitosan nanoparticles with the best results achieved for the chitosan grafted with poly(N-vinyl pyrrolidone). |
BibTeX:
@article{Ways2022,
author = {Ways, T.M.M. and Filippov, S.K. and Maji, S. and Glassner, M. and Cegłowski, M. and Hoogenboom, R. and King, S. and Lau, W.M. and Khutoryanskiy, V.V.},
title = {Mucus-penetrating nanoparticles based on chitosan grafted with various non-ionic polymers: Synthesis, structural characterisation and diffusion studies},
journal = {J. Colloid Interface Sci.},
year = {2022},
volume = {626},
pages = {251--264},
doi = {10.1016/j.jcis.2022.06.126}
}
|
| Yue Y, Dziȩgielewska A, Hull S, Krok F, Whiteley R, Toms H, Malys M, Zhang M, Yan H and Abrahams I (2022), "Local structure in a tetravalent-substituent BIMEVOX system: BIGEVOX", J. Mater. Chem. A. Vol. 10(7), pp. 3793-3807. |
| Abstract: Bi2MExlV1-xO5.5-(5-l)x/2-δ (BIMEVOX, ME = dopant, l = valency) systems are a family of fast oxide ion conductors that show very high ionic conductivity at low and intermediate temperatures. Despite being studied for almost 30 years, the extent of the disorder in these systems has meant that many questions about the detail of the local structure remain unanswered. In this work, reverse Monte Carlo analysis of a combination of synchrotron X-ray and neutron diffraction data has been used to examine the defect structure in the tetravalent-substituent system, Bi2V1-xGexO5.5-x/2-δ. Although the ordered α-phase is seen at room temperature over an extensive compositional range, the incommensurately ordered γ′-phase can be quenched to room temperature at x = 0.35, which on heating above 500 °C, undergoes a transition to the fully disordered tetragonal γ-phase. Germanium is suggested to mainly adopt a tetrahedral coordination environment in both these phases, while vanadium shows different local geometries including tetrahedral, pentacoordinate and octahedral, the relative proportions of which change with temperature. Oxygen vacancies are found to be mainly distributed in equatorial sites around Ge and V, with a higher concentration of apical vacancies in the γ′-phase. A non-random deficiency in next-nearest-neighbour vacancy pairs in the 〈100〉 tetragonal direction is identified, consistent with the known superlattice ordering seen in lower x-value compositions, suggesting short range ordering of oxide ions/vacancies. Such ordering is known to contribute to a lowering of oxide ion conductivity and may well be a factor in lowering the conductivity of the γ-phase BIMEVOXes. These data are supported by 51V solid state NMR results as well as Raman spectroscopic data, with electrical characterization by A.C. impedance spectroscopy. |
BibTeX:
@article{Yue2022,
author = {Yue, Y. and Dziȩgielewska, A. and Hull, S. and Krok, F. and Whiteley, R.M. and Toms, H. and Malys, M. and Zhang, M. and Yan, H. and Abrahams, I.},
title = {Local structure in a tetravalent-substituent BIMEVOX system: BIGEVOX},
journal = {J. Mater. Chem. A},
year = {2022},
volume = {10},
number = {7},
pages = {3793--3807},
doi = {10.1039/d1ta07547k}
}
|
| Zajdel P, Madden D, Babu R, Tortora M, Mirani D, Tsyrin N, Bartolomé L, Amayuelas E, Fairen-Jimenez D, Lowe A, Meloni S and Grosu Y (2022), "Turning Molecular Springs into Nano-Shock Absorbers: The Effect of Macroscopic Morphology and Crystal Size on the Dynamic Hysteresis of Water Intrusion-Extrusion into-from Hydrophobic Nanopores", ACS Appl. Mater. Interfaces. Vol. 14(23), pp. 26699-26713. |
| Abstract: Controlling the pressure at which liquids intrude (wet) and extrude (dry) a nanopore is of paramount importance for a broad range of applications, such as energy conversion, catalysis, chromatography, separation, ionic channels, and many more. To tune these characteristics, one typically acts on the chemical nature of the system or pore size. In this work, we propose an alternative route for controlling both intrusion and extrusion pressures via proper arrangement of the grains of the nanoporous material. To prove the concept, dynamic intrusion-extrusion cycles for powdered and monolithic ZIF-8 metal-organic framework were conducted by means of water porosimetry and in operando neutron scattering. We report a drastic increase in intrusion-extrusion dynamic hysteresis when going from a fine powder to a dense monolith configuration, transforming an intermediate performance of the ZIF-8 + water system (poor molecular spring) into a desirable shock-absorber with more than 1 order of magnitude enhancement of dissipated energy per cycle. The obtained results are supported by MD simulations and pave the way for an alternative methodology of tuning intrusion-extrusion pressure using a macroscopic arrangement of nanoporous material. |
BibTeX:
@article{Zajdel2022,
author = {Zajdel, P. and Madden, D.G. and Babu, R. and Tortora, M. and Mirani, D. and Tsyrin, N.N. and Bartolomé, L. and Amayuelas, E. and Fairen-Jimenez, D. and Lowe, A.R. and Meloni, S. and Grosu, Y.},
title = {Turning Molecular Springs into Nano-Shock Absorbers: The Effect of Macroscopic Morphology and Crystal Size on the Dynamic Hysteresis of Water Intrusion-Extrusion into-from Hydrophobic Nanopores},
journal = {ACS Appl. Mater. Interfaces},
year = {2022},
volume = {14},
number = {23},
pages = {26699--26713},
doi = {10.1021/acsami.2c04314}
}
|
| Żywczak A, Gondek Ł, Czub J, Janusz P, Selvaraj NB and Takasaki A (2022), "Physical Properties of Ti45Zr38Fe17 Alloy and Its Amorphous Hydride", Energies., Jun, 2022. Vol. 15(12), pp. 4236. |
| Abstract: The alloys based on Ti-Zr are considered an excellent candidate for hydrogen storage applications. In this communication, we report the results of Fe substitution for Ni in the well-known Ti45Zr38Ni17 compound. The parent and related compounds can be obtained as amorphous powders, transforming into the quasicrystalline phase (i-phase) after annealing. The amorphous Ti45Zr38Fe17 phase is transformed into the icosahedral quasicrystalline state, and it is a quasi-continuous process. The i-phase is well-developed close to 500 °C. At higher temperatures, the quasicrystal structure transforms into the other phase: the w-phase (an approximant to the crystalline phase) and another crystal phase with a small addition of the FeZr3 and the Fe2(ZrTi)3. The amorphous Ti45Zr38Fe17 phases can be hydrogenated while maintaining the amorphous nature, which constitutes another very fascinating research field for our group. The investigated alloy shows a good capacity for gaseous H2 at level 2.54 wt.% at elevated temperatures. The ferromagnetic signal of the amorphous TiZrFe comes from magnetic nanocrystallites in the amorphous matrix. After heating, the magnetic signal significantly decreases due to the lack of long-range magnetic ordering in the i-phase of the Ti45Zr38Fe17 alloy. |
BibTeX:
@article{Zywczak2022,
author = {Żywczak, Antoni and Gondek, Łukasz and Czub, Joanna and Janusz, Piotr and Selvaraj, Nivas Babu and Takasaki, Akito},
title = {Physical Properties of Ti45Zr38Fe17 Alloy and Its Amorphous Hydride},
journal = {Energies},
year = {2022},
volume = {15},
number = {12},
pages = {4236},
url = {https://www.mdpi.com/1996-1073/15/12/4236},
doi = {10.3390/en15124236}
}
|
| Baczmański A, Kot P, Wroński S, Wróbel M, Wroński M, Pilch J, Muzyka M, Wierzbanowski K, Zhao Y, Le Joncour L, François M and Panicaud B (2021), "Direct diffraction measurement of critical resolved shear stresses and stress localisation in magnesium alloy", Mater. Sci. Eng. A., Jan, 2021. Vol. 801, pp. 140400. |
| Abstract: The main purpose of this work is to develop neutron diffraction methodology in order to determine stresses localised in polycrystalline grains during elastoplastic deformation, directly from experiment. As a result, for the first time, the von Mises stress for chosen grain orientations and Critical Resolved Shear Stresses (CRSS) for active slip systems were unambiguously measured without the help of crystallographic models, which introduce different theoretical assumptions. The stresses measured for groups of grains and the determined CRSS values are important characteristics of a material, which allow to study plastic deformation in textured material at different scales: slip system and grain, which play a key role in mechanical properties and formability of the material. The new method was successfully tested and applied to textured AZ31 alloy subjected to tensile deformation and the components of stress tensor were for the first time determined from measured lattice strains corresponding to chosen orientations of crystallite lattice. The obtained results positively verified hypotheses that, during plastic deformation, a large difference in the hardness as well as in the localised stresses occurs for grains having different lattice orientations. It was found directly from experiment that, the activation of basal glide, having small CRSS, does not lead to significant plastic deformation, and the activation of other non-basal systems (with higher CRSS) induces the development of plasticity at the macroscopic scale. The early plastic deformation occurring due to slip on basal system is small but it can destructively affect fatigue life, limiting applicability of the material for structural components. Finally, the comparison of experimental results with a modified version of Elastic-Plastic Self-Consistent (EPSC) model showed its capability to simulate the mechanical behaviour of such materials. |
BibTeX:
@article{Baczmanski2021,
author = {Baczmański, A. and Kot, P. and Wroński, S. and Wróbel, M. and Wroński, M. and Pilch, J. and Muzyka, M. and Wierzbanowski, K. and Zhao, Y. and Le Joncour, L. and François, M. and Panicaud, B.},
title = {Direct diffraction measurement of critical resolved shear stresses and stress localisation in magnesium alloy},
journal = {Mater. Sci. Eng. A},
year = {2021},
volume = {801},
pages = {140400},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0921509320314647},
doi = {10.1016/j.msea.2020.140400}
}
|
| Baran S, Deptuch A, Hoser A, Penc B, Tyvanchuk Y and Szytuła A (2021), "Crystal and magnetic structures of R2Ni1.78In compounds (R = Tb, Ho, Er and Tm)", Acta Crystallogr. Sect. B Struct. Sci. Cryst. Eng. Mater., Oct, 2021. Vol. 77(5), pp. 824-832. |
| Abstract: The crystal and magnetic structures in R 2Ni1.78In (R = Ho, Er and Tm) have been studied by neutron diffraction. The compounds crystallize in a tetragonal crystal structure of the Mo2FeB2 type (space group P4/mbm). At low temperatures, the magnetic moments, localized solely on the rare earth atoms, form antiferromagnetic structures described by the propagation vector k = [kx , kx , ½], with kx equal to ¼ for R = Er and Tm or 0.3074 (4) for R = Ho. The magnetic moments are parallel to the c axis for R = Ho or lie within the (001) plane for R = Er and Tm. The obtained magnetic structures are discussed on the basis of symmetry analysis. The rare earth magnetic moments, determined from neutron diffraction data collected at 1.6 K, are 6.5 (1) μB (Er) and 6.09 (4) μB (Tm), while in the incommensurate modulated magnetic structure in Ho2Ni1.78In the amplitude of modulation of the Ho magnetic moment is 7.93 (8) μB. All these values are smaller than those expected for the respective free R 3+ ions. A symmetry analysis of the magnetic structure in Tb2Ni1.78In is also included, as such information is missing from the original paper [Szytuła, Baran, Hoser, Kalychak, Penc & Tyvanchuk (2013). Acta Phys. Pol. A, 124, 994-997]. In addition, the results of magnetometric measurements are reported for Tm2Ni1.78In. The compound shows antiferromagnetic ordering below the Néel temperature of 4.5 K. Its magnetic properties are found to originate from magnetic moments localized solely on the thulium atoms (the nickel atoms remain non-magnetic in Tm2Ni1.78In). The reduction of rare earth magnetic moments in the ordered state in R 2Ni1.78In (R = Tb, Ho, Er and Tm) and the change in direction of the moments indicate the influence of the crystalline electric field (CEF) on the stability of the magnetic order in the investigated compounds. |
BibTeX:
@article{Baran2021,
author = {Baran, Stanisław and Deptuch, Aleksandra and Hoser, Andreas and Penc, Bogusław and Tyvanchuk, Yuriy and Szytuła, Andrzej},
title = {Crystal and magnetic structures of R2Ni1.78In compounds (R = Tb, Ho, Er and Tm)},
journal = {Acta Crystallogr. Sect. B Struct. Sci. Cryst. Eng. Mater.},
year = {2021},
volume = {77},
number = {5},
pages = {824--832},
url = {https://scripts.iucr.org/cgi-bin/paper?S2052520621008179},
doi = {10.1107/S2052520621008179}
}
|
| Baran S, Deptuch A, Penc B, Hoser A and Szytula A (2021), "Symmetry analysis of complex magnetic structure in monoclinically distorted Er3Cu4Sn4", Acta Crystallogr. Sect. B Struct. Sci. Cryst. Eng. Mater., Apr, 2021. Vol. 77(2), pp. 219-224. |
| Abstract: The magnetic structure in Er3Cu4Sn4 has been determined using high-resolution powder neutron diffraction, supported by symmetry analysis. At low temperatures, Er3Cu4Sn4 assumes a crystal structure of the Tm3Cu4Sn4 type (in the monoclinic space group C2/m). The Er atoms occupy two distinct Wyckoff sites: 2c and 4i. It has been found that the Er magnetic moments on the 2c site form a commensurate antiferromagnetic structure (k 1 = [0, 0, ½]) below 6K. The magnetic moments reach 8.91(8)μB at 1.4K and are parallel to the b axis. The Er magnetic moments on the 4i site order below 2K and form an incommensurate antiferromagnetic sine-modulated structure (k 2 = [1, 0.4667(1), ½]), with magnetic moments lying in the ac plane and perpendicular to the a axis. The amplitude of modulation equals 8.7(1)μB at 1.4K. |
BibTeX:
@article{Baran2021a,
author = {Baran, Stanislaw and Deptuch, Aleksandra and Penc, Boguslaw and Hoser, Andreas and Szytula, Andrzej},
title = {Symmetry analysis of complex magnetic structure in monoclinically distorted Er3Cu4Sn4},
journal = {Acta Crystallogr. Sect. B Struct. Sci. Cryst. Eng. Mater.},
year = {2021},
volume = {77},
number = {2},
pages = {219--224},
url = {https://scripts.iucr.org/cgi-bin/paper?S205252062100127X},
doi = {10.1107/S205252062100127X}
}
|
| Baran S, Deptuch A, Reehuis M, Tyvanchuk Y, Yokaichiya F and Szytuła A (2021), "Complex magnetic ordering in RE5Pd2In4 (RE = Tb-Tm) compounds investigated by neutron diffraction and magnetometric measurements", J. Alloys Compd., Oct, 2021. Vol. 877, pp. 160171. |
| Abstract: The RE5Pd2In4 (RE = Tb-Tm) compounds crystallize with the orthorhombic Lu5Ni2In4-type crystal structure (Pbam space group). In this work we report results of structural and magnetic studies by means of X-ray and neutron diffraction as well as dc and ac magnetometric data. Magnetic susceptibility and neutron diffraction data revealed rare-earth moments order at low temperatures with complex magnetic structures showing a cascade of temperature-induced transitions. The magnetic ordering temperatures are found to be 97, 88, 28.5, 16.5 and 4.3 K for RE = Tb, Dy, Ho, Er and Tm, respectively. Magnetic structures related to the propagation vector k→1=[0,0,0] are found just below the magnetic ordering temperatures in majority of the investigated compounds (RE = Tb-Er). Below the Curie temperature TC they have purely ferromagnetic character in Tb5Pd2In4 and Dy5Pd2In4. A ferrimagnetic order finally sets at lower temperatures in Dy5Pd2In4, while in Ho5Pd2In4 two magnetic phases related to k→1 are observed: the antiferromagnetic one (phase I) and the ferrimagnetic one (phase II, coexisting with phase I at lower temperatures). Er5Pd2In4 is a canted antiferromagnet with additional ferromagnetic component developing at lower temperatures. A purely antiferromagnetic component of magnetic structure with enlarged magnetic unit cell appears with decreasing temperature in Tb5Pd2In4 (k→2=[0,[Formula presented],0] and k→3=[0,[Formula presented],[Formula presented]]) while in Ho5Pd2In4 such component (k→4=[[Formula presented],0,0]) is present within whole temperature range below the magnetic ordering temperature. Magnetic structure of Tm5Pd2In4, exceptionally, has no k→1 component, but is an antiferromagnetic incommensurate one related to two propagation vectors: k→5=[0.073(3),0.451(1),[Formula presented]] and k→6=[0,0.335(2),[Formula presented]]. In majority of the compounds (RE = Tb-Er) the first rare-earth 4g site (noted as 4g1) orders at lower temperature than two remaining sites (2a and 4g2). The direction of the magnetic moments depends on rare-earth element involved and indicates an influence of single-ion anisotropy in the crystalline electric field (CEF). |
BibTeX:
@article{Baran2021b,
author = {Baran, Stanisław and Deptuch, Aleksandra and Reehuis, Manfred and Tyvanchuk, Yuriy and Yokaichiya, Fabiano and Szytuła, Andrzej},
title = {Complex magnetic ordering in RE5Pd2In4 (RE = Tb-Tm) compounds investigated by neutron diffraction and magnetometric measurements},
journal = {J. Alloys Compd.},
year = {2021},
volume = {877},
pages = {160171},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838821015802},
doi = {10.1016/j.jallcom.2021.160171}
}
|
| Chorażewski M, Zajdel P, Feng T, Luo D, Lowe A, Brown C, Leão J, Li M, Bleuel M, Jensen G, Faik A and Grosu Y (2021), "Compact Thermal Actuation by Water and Flexible Hydrophobic Nanopore", ACS Nano. Vol. 15(5), pp. 9048-9056. |
| Abstract: Efficient and compact energy conversion is at the heart of the sustainable development of humanity. In this work it is demonstrated that hydrophobic flexible nanoporous materials can be used for thermal-to-mechanical energy conversion when coupled with water. In particular, a reversible nonhysteretic wetting-drying (contraction-expansion) cycle provoked by periodic temperature fluctuations was realized for water and a superhydrophobic nanoporous Cu2(tebpz) MOF (tebpz = 3,3′,5,5′-tetraethyl-4,4′-bipyrazolate). A thermal-to-mechanical conversion efficiency of ∼30% was directly recorded by high-precision PVT-calorimetry, while the operational cycle was confirmed by in operando neutron scattering. The obtained results provide an alternative approach for compact energy conversion exploiting solid-liquid interfacial energy in nanoscopic flexible heterogeneous systems. |
BibTeX:
@article{Chorazewski2021,
author = {Chorażewski, M. and Zajdel, P. and Feng, T. and Luo, D. and Lowe, A.R. and Brown, C.M. and Leão, J.B. and Li, M. and Bleuel, M. and Jensen, G. and Faik, A. and Grosu, Y.},
title = {Compact Thermal Actuation by Water and Flexible Hydrophobic Nanopore},
journal = {ACS Nano},
year = {2021},
volume = {15},
number = {5},
pages = {9048--9056},
doi = {10.1021/acsnano.1c02175}
}
|
| Demir E, Mirzayev M, Popov E, Horodek P, Genov I, Siemek K, Mirzayeva D, Turchenko V, Bulavin M, Beskrovnyi A, Valizade A, Akhundzada H and Karaaslan S (2021), "Effects of high-energetic 3He+ ion irradiation on tungsten-based composites", Vacuum., Feb, 2021. Vol. 184, pp. 109934. |
| Abstract: The interaction of plasma and its encompassing materials with one another is one of the principle designing issues of fusion reactors. Tungsten is considered one of the primary candidate materials in fusion applications due to its superior properties. In this work, we doped vanadium carbide powders to the tungsten matrix to enhance the properties of tungsten alloys. Tungsten-based composites, which irradiated with 2.5 MeV 3He+ ions at room temperature, were analyzed by atomic force microscopy (AFM) in order to obtain surface morpohologies after irradiation. Helium ion irradiated tungsten-based composites were studied by using XRD, neutron diffraction technique, raman spectroscopy, and positron annihilation spectroscopy to reveal the microstructural changes. XRD and ND analyses clarified the changes in the crystal structures of the tungsten-based materials after He ion irradiation. The simulation of radiation damage and the calculation of displacements per atom (DPA) was also determined by the SRIM code. SRIM showed that the maximum helium concentration in the specimens takes place in the depth range of 58–65 nm. The crystallite size of tungsten-based composites slightly increased after helium ion irradiation. AFM results revealed that the maximum size of bubbles on the surface of tungsten-based composites shape under 100 nm. Positron annihilation spectroscopy studies of the specimens have been discussed before and after 3He+ ion irradiation. |
BibTeX:
@article{Demir2021,
author = {Demir, E. and Mirzayev, M.N. and Popov, E.P. and Horodek, P. and Genov, I.G. and Siemek, K. and Mirzayeva, D.M. and Turchenko, V.A. and Bulavin, M. and Beskrovnyi, A.I. and Valizade, A.H. and Akhundzada, H.V. and Karaaslan, S.I.},
title = {Effects of high-energetic 3He+ ion irradiation on tungsten-based composites},
journal = {Vacuum},
year = {2021},
volume = {184},
pages = {109934},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0042207X20307946},
doi = {10.1016/j.vacuum.2020.109934}
}
|
| Drużbicki K, Lavén R, Armstrong J, Malavasi L, Fernandez-Alonso F and Karlsson M (2021), "Cation Dynamics and Structural Stabilization in Formamidinium Lead Iodide Perovskites", J. Phys. Chem. Lett.. Vol. 12(14), pp. 3503-3508. |
| Abstract: The vibrational dynamics of pure and methylammonium-doped formamidinium lead iodide perovskites (FAPbI3) has been investigated by high-resolution neutron spectroscopy. For the first time, we provide an exhaustive and accurate analysis of the cation vibrations and underlying local structure around the organic moiety in these materials using first-principles electronic-structure calculations validated by the neutron data. Inelastic neutron scattering experiments on FAPbI3 provide direct evidence of the formation of a low-temperature orientational glass, unveiling the physicochemical origin of phase metastability in the tetragonal structure. Further analysis of these data provides a suitable starting point to explore and understand the stabilization of the perovskite framework via doping with small amounts of organic cations. In particular, we find that the hydrogen-bonding interactions around the formamidinium cations are strengthened as a result of cage deformation. This synergistic effect across perovskite cages is accompanied by a concomitant weakening of the methylammonium interactions with the surrounding framework. |
BibTeX:
@article{Druzbicki2021,
author = {Drużbicki, K. and Lavén, R. and Armstrong, J. and Malavasi, L. and Fernandez-Alonso, F. and Karlsson, M.},
title = {Cation Dynamics and Structural Stabilization in Formamidinium Lead Iodide Perovskites},
journal = {J. Phys. Chem. Lett.},
year = {2021},
volume = {12},
number = {14},
pages = {3503--3508},
doi = {10.1021/acs.jpclett.1c00616}
}
|
| Dzięgielewska A, Malys M, Wróbel W, Hull S, Yue Y, Krok F and Abrahams I (2021), "Bi2V1-x(Mg0.25Cu0.25Ni0.25Zn0.25)xO5.5-3x/2: A high entropy dopant BIMEVOX", Solid State Ionics., Feb, 2021. Vol. 360, pp. 115543. |
| Abstract: A high entropy dopant approach has been used to prepare a new BIMEVOX ceramic system, Bi2V1-x(Mg0.25Cu0.25Ni0.25Zn0.25)xO5.5-3x/2. Structures were investigated using a combination of X-ray and neutron powder diffraction, with electrical characterisation by A.C. impedance spectroscopy. A γ-type phase is observed at room temperature over the compositional range 0.10 ≤ x ≤ 0.30, the upper limit of which is beyond that seen for all the single substituted systems based on these substituents, apart from BIMGVOX. No stabilisation of the fully disordered γ-phase is seen at room temperature over this compositional range, with only the incommensurately ordered γ'-phase evident below around 450 °C. Changes in defect structure are used to explain an apparent transition in the compositional variation of lattice parameters. The HE dopant approach has no detrimental effect on ionic conductivity, with values comparable to those of the single substituted systems based on the component oxides. |
BibTeX:
@article{Dziegielewska2021,
author = {Dziegielewska, A. and Malys, M. and Wrobel, W. and Hull, S. and Yue, Y. and Krok, F. and Abrahams, I.},
title = {Bi2V1-(Mg0.25Cu0.25Ni0.25Zn0.25) O5.5-3/2: A high entropy dopant BIMEVOX},
journal = {Solid State Ionics},
year = {2021},
volume = {360},
pages = {115543},
url = {https://linkinghub.elsevier.com/retrieve/pii/S016727382030597X},
doi = {10.1016/j.ssi.2020.115543}
}
|
| Episcopo N, Chang PH, Heitmann TW, Wangmo K, Mckamey Guthrie J, Fitta M, Klein RA, Poudel N, Gofryk K, Zope RR, Brown CM and Nair HS (2021), "Magnetic structure, excitations and short-range order in honeycomb Na2Ni2TeO6", J. Phys. Condens. Matter., Sep, 2021. Vol. 33(37), pp. 375803. |
| Abstract: Na2Ni2TeO6 has a layered hexagonal structure with a honeycomb lattice constituted by Ni2+ and a chiral charge distribution of Na+ that resides between the Ni layers. In the present work, the antiferromagnetic (AFM) transition temperature of Na2Ni2TeO6 is confirmed at T N ≈ 27 K, and further, it is found to be robust up to 8 T magnetic field and 1.2 GPa external pressure; and, without any frequency-dependence. Slight deviations from nominal Na-content (up to 5%) does not seem to influence the magnetic transition temperature, T N. Isothermal magnetization curves remain almost linear up to 13 T. Our analysis of neutron diffraction data shows that the magnetic structure of Na2Ni2TeO6 is faithfully described by a model consisting of two phases described by the commensurate wave vectors kc, (0.5 0 0) and (0.5 0 0.5), with an additional short-range order component incorporated in to the latter phase. Consequently, a zig-zag long-range ordered magnetic phase of Ni2+ results in the compound, mixed with a short-range ordered phase, which is supported by our specific heat data. Theoretical computations based on density functional theory predict predominantly in-plane magnetic exchange interactions that conform to a J 1-J 2-J 3 model with a strong J 3 term. The computationally predicted parameters lead to a reliable estimate for T N and the experimentally observed zig-zag magnetic structure. A spin wave excitation in Na2Ni2TeO6 at E ≈ 5 meV at T = 5 K is mapped out through inelastic neutron scattering experiments, which is reproduced by linear spin wave theory calculations using the J values from our computations. Our specific heat data and inelastic neutron scattering data strongly indicate the presence of short-range spin correlations, at T > T N, stemming from incipient AFM clusters. |
BibTeX:
@article{Episcopo2021,
author = {Episcopo, Nathan and Chang, Po Hao and Heitmann, Thomas W and Wangmo, Kinley and Mckamey Guthrie, James and Fitta, Magdalena and Klein, Ryan A and Poudel, Narayan and Gofryk, Krzysztof and Zope, Rajendra R and Brown, Craig M and Nair, Harikrishnan S},
title = {Magnetic structure, excitations and short-range order in honeycomb Na2Ni2TeO6},
journal = {J. Phys. Condens. Matter},
year = {2021},
volume = {33},
number = {37},
pages = {375803},
url = {https://iopscience.iop.org/article/10.1088/1361-648X/ac0ea6},
doi = {10.1088/1361-648X/ac0ea6}
}
|
| Fang M-H, Lin J-C, Huang W-T, Majewska N, Barzowska J, Mahlik S, Pang WK, Lee J-F, Sheu H-S and Liu R-S (2021), "Linking Macro- and Micro-structural Analysis with Luminescence Control in Oxynitride Phosphors for Light-Emitting Diodes", Chem. Mater., Oct, 2021. Vol. 33(19), pp. 7897-7904. |
| Abstract: Eu2+-doped UCr4C4-type oxynitride phosphors are emerging innovative materials to replace oxide and nitride phosphors for high-end light-emitting devices. However, the synthesis of high-purity phosphors and controlling the O/N ratio remain challenging. Here, we synthesized a series of Sr0.98Li2.5 + zAl1.5 - zO3 + 2zN1 - 2z:0.02Eu phosphors by precursor engineering, and these products showed an unexpected redshift from 583 to 620 nm. Joint refinement combining synchrotron X-ray diffraction and neutron powder diffraction was conducted to determine macro-structural properties. Extended X-ray absorption fine structure spectra revealed the micro-structural properties around the luminescent centers. The effects on photoluminescence from the first-shelled O/N ligands and the second-shelled Li/Al ions were demonstrated in detail. Finally, the light-emitting diode packages constructed using our phosphor revealed higher luminous efficiency of radiation and luminous efficacy than the SrLiAl3N4:Eu comparator. This study provided the basis for developing novel oxynitride phosphors and insights into the structural analysis from the macro and micro perspectives. |
BibTeX:
@article{Fang2021,
author = {Fang, Mu-Huai and Lin, Jia-Cheng and Huang, Wen-Tse and Majewska, Natalia and Barzowska, Justyna and Mahlik, Sebastian and Pang, Wei Kong and Lee, Jyh-Fu and Sheu, Hwo-Shuenn and Liu, Ru-Shi},
title = {Linking Macro- and Micro-structural Analysis with Luminescence Control in Oxynitride Phosphors for Light-Emitting Diodes},
journal = {Chem. Mater.},
year = {2021},
volume = {33},
number = {19},
pages = {7897--7904},
url = {https://pubs.acs.org/doi/10.1021/acs.chemmater.1c02990},
doi = {10.1021/acs.chemmater.1c02990}
}
|
| Fidrysiak M and Spałek J (2021), "Universal collective modes from strong electronic correlations: Modified 1/ Nf theory with application to high- Tc cuprates", Phys. Rev. B., Apr, 2021. Vol. 103(16), pp. 165111. |
| Abstract: A nonzero-temperature technique for strongly correlated electron lattice systems, combining elements of both variational wave function (VWF) approach and expansion in the inverse number of fermionic flavors (1/Nf), is developed. The departure point, VWF method, goes beyond the renormalized mean-field theory and provides semiquantitative description of principal equilibrium properties of high-Tc superconducting cuprates. The developed here scheme of VWF+1/Nf, in the leading order provides dynamical spin and charge responses around the VWF solution, generalizing the weak-coupling spin-fluctuation theory to the regime of strong correlations. Thermodynamic corrections to the correlated saddle-point state arise systematically at consecutive orders. Explicitly, VWF+1/Nf is applied to evaluate dynamical response functions for the hole-doped Hubbard model and compared with available determinant quantum Monte Carlo data, yielding a good overall agreement in the regime of coherent collective-mode dynamics. The emergence of well-defined spin and charge excitations from the incoherent continua is explicitly demonstrated and a nonmonotonic dependence of the charge-excitation energy on the interaction magnitude is found. The charge mode energy saturates slowly when approaching the strong-coupling limit, which calls for a reevaluation of the t-J-model approach to the charge dynamics in favor of more general t-J-U and t-J-U-V models. The results are also related to recent inelastic resonant x-ray and neutron-scattering experiments for the high-Tc cuprates. |
BibTeX:
@article{Fidrysiak2021,
author = {Fidrysiak, Maciej and Spałek, Józef},
title = {Universal collective modes from strong electronic correlations: Modified 1/ Nf theory with application to high- Tc cuprates},
journal = {Phys. Rev. B},
year = {2021},
volume = {103},
number = {16},
pages = {165111},
url = {https://link.aps.org/doi/10.1103/PhysRevB.103.165111},
doi = {10.1103/PhysRevB.103.165111}
}
|
| Gadalińska E, Pawliszak Ł and Moneta G (2021), "Laser Powder Bed Fusion and Selective Laser Melted Components Investigated with Highly Penetrating Radiation", Fatigue Aircr. Struct.. Vol. 2021(13), pp. 81-98. |
| Abstract: Methods of incremental manufacturing, i.e. 3D printing, have been experiencing significant growth in recent years, both in terms of the development of modern technologies dedicated to various applications, and in terms of optimizing the parameters of the process itself so as to ensure the desired mechanical and strength properties of the parts produced in this way. High hopes are currently being pinned on the use of highly penetrating types of radiation, i.e. synchrotron and/or neutron radiation, for quantitative identification of parameters characterizing objects produced by means of 3D printing. Thanks to diffraction methodologies, it is feasible to obtain input information to optimize 3D printing procedures not only for finished prints but also to monitor in situ printing processes. Thanks to these methodologies, it is possible to obtain information on parameters that are critical from the perspective of application of such obtained elements as stresses generated during the printing procedure itself as well as residual stresses after printing. This parameter, from the point of view of tensile strength, compression strength as well as fatigue strength, is crucial and determines the possibility of introducing elements produced by incremental methods into widespread industrial use. |
BibTeX:
@article{Gadalinska2021,
author = {Gadalińska, E. and Pawliszak, Ł. and Moneta, G.},
title = {Laser Powder Bed Fusion and Selective Laser Melted Components Investigated with Highly Penetrating Radiation},
journal = {Fatigue Aircr. Struct.},
year = {2021},
volume = {2021},
number = {13},
pages = {81--98},
doi = {10.2478/fas-2021-0008}
}
|
| Gochev GG, Kovalchuk VI, Aksenenko EV, Fainerman VB and Miller R (2021), "β-Lactoglobulin Adsorption Layers at the Water/Air Surface: 5. Adsorption Isotherm and Equation of State Revisited, Impact of pH", Colloids and Interfaces., Mar, 2021. Vol. 5(1), pp. 14. |
| Abstract: The theoretical description of the adsorption of proteins at liquid/fluid interfaces suffers from the inapplicability of classical formalisms, which soundly calls for the development of more complicated adsorption models. A Frumkin-type thermodynamic 2-d solution model that accounts for nonidealities of interface enthalpy and entropy was proposed about two decades ago and has been continuously developed in the course of comparisons with experimental data. In a previous paper we investigated the adsorption of the globular protein β-lactoglobulin at the water/air interface and used such a model to analyze the experimental isotherms of the surface pressure, Π(c), and the frequency-, f-, dependent surface dilational viscoelasticity modulus, E(c)f, in a wide range of protein concentrations, c, and at pH 7. However, the best fit between theory and experiment proposed in that paper appeared incompatible with new data on the surface excess, Γ, obtained from direct measurements with neutron reflectometry. Therefore, in this work, the same model is simultaneously applied to a larger set of experimental dependences, e.g., Π(c), Γ(c), E(Π)f, etc., with E-values measured strictly in the linear viscoelasticity regime. Despite this ambitious complication, a best global fit was elaborated using a single set of parameter values, which well describes all experimental dependencies, thus corroborating the validity of the chosen thermodynamic model. Furthermore, we applied the model in the same manner to experimental results obtained at pH 3 and pH 5 in order to explain the well-pronounced effect of pH on the interfacial behavior of β-lactoglobulin. The results revealed that the propensity of β-lactoglobulin globules to unfold upon adsorption and stretch at the interface decreases in the order pH 3 > pH 7 > pH 5, i.e., with decreasing protein net charge. Finally, we discuss advantages and limitations in the current state of the model. |
BibTeX:
@article{Gochev2021,
author = {Gochev, Georgi G. and Kovalchuk, Volodymyr I. and Aksenenko, Eugene V. and Fainerman, Valentin B. and Miller, Reinhard},
title = {β-Lactoglobulin Adsorption Layers at the Water/Air Surface: 5. Adsorption Isotherm and Equation of State Revisited, Impact of pH},
journal = {Colloids and Interfaces},
year = {2021},
volume = {5},
number = {1},
pages = {14},
url = {https://www.mdpi.com/2504-5377/5/1/14},
doi = {10.3390/colloids5010014}
}
|
| Hetmańczyk J, Hetmańczyk Ł, Nowicka-Scheibe J, Pawlukojć A, Maurin JK and Schilf W (2021), "Structural, Thermal, and Vibrational Properties of N,N-Dimethylglycine–Chloranilic Acid — A New Co-Crystal Based on an Aliphatic Amino Acid", Materials (Basel)., Jun, 2021. Vol. 14(12), pp. 3292. |
| Abstract: The new complex of N,N-Dimethylglycine (DMG) with chloranilic acid (CLA) was synthesized and examined for thermal, structural, and dynamical properties. The structure of the reaction product between DMG and CLA was investigated in a deuterated dimethyl sulfoxide (DMSO-d6) solution and in the solid state by Nuclear Magnetic Resonance (NMR) (Cross Polarization Magic Angle Spinning-CPMAS NMR). The formation of the 1:1 complex of CLA and DMG in the DMSO solution was also confirmed by diffusion measurement. X-ray single crystal diffraction results revealed that the N,N-dimethylglycine–chloranilic acid (DMG+–CLA−) complex crystallizes in the centrosymmetric triclinic P-1 space group. The X-ray diffraction and NMR spectroscopy show the presence of the protonated form of N,N-dimethylglycine and the deprotonated form of chloranilic acid molecules. The vibrational properties of the co-crystal were investigated by the use of neutron (INS), infrared (IR), and Raman (RS) spectroscopies, as well as the density functional theory (DFT) with periodic boundary conditions. From the band shape analysis of the N–CH3 bending vibration, we can conclude that the CH3 groups perform fast (τR ≈ 10−11 to 10‒13 s) reorientational motions down to a temperature of 140 K, with activation energy at ca. 6.7 kJ mol−1. X-ray diffraction and IR investigations confirm the presence of a strong N+–HtextperiodcenteredtextperiodcenteredtextperiodcenteredO− hydrogen bond in the studied co-crystal. |
BibTeX:
@article{Hetmanczyk2021,
author = {Hetmańczyk, Joanna and Hetmańczyk, Łukasz and Nowicka-Scheibe, Joanna and Pawlukojć, Andrzej and Maurin, Jan K. and Schilf, Wojciech},
title = {Structural, Thermal, and Vibrational Properties of N,N-Dimethylglycine–Chloranilic Acid—A New Co-Crystal Based on an Aliphatic Amino Acid},
journal = {Materials (Basel).},
year = {2021},
volume = {14},
number = {12},
pages = {3292},
url = {https://www.mdpi.com/1996-1944/14/12/3292},
doi = {10.3390/ma14123292}
}
|
| Hetmańczyk Ł, Goremychkin EA, Waliszewski J, Vener MV, Lipkowski P, Tolstoy PM and Filarowski A (2021), "Spectroscopic Identification of Hydrogen Bond Vibrations and Quasi-Isostructural Polymorphism in N-Salicylideneaniline", Molecules., Aug, 2021. Vol. 26(16), pp. 5043. |
| Abstract: The ortho-hydroxy aryl Schiff base 2-[(E)-(phenylimino)methyl]phenol and its deutero-derivative have been studied by the inelastic incoherent neutron scattering (IINS), infrared (IR) and Raman experimental methods, as well as by Density Functional Theory (DFT) and Density-Functional Perturbation Theory (DFPT) simulations. The assignments of vibrational modes within the 3500–50 cm−1 spectral region made it possible to state that the strong hydrogen bond in the studied compound can be classified as the so-called quasi-aromatic bond. The isotopic substitution supplemented by the results of DFT calculations allowed us to identify vibrational bands associated with all five major hydrogen bond vibrations. Quasi-isostructural polymorphism of 2-[(E)-(phenylimino)methyl]phenol (SA) and 2-[(E)-(phenyl-D5-imino)methyl]phenol (SA-C6D5) has been studied by powder X-ray diffraction in the 20–320 K temperature range. |
BibTeX:
@article{Hetmanczyk2021a,
author = {Hetmańczyk, Łukasz and Goremychkin, Eugene A. and Waliszewski, Janusz and Vener, Mikhail V. and Lipkowski, Paweł and Tolstoy, Peter M. and Filarowski, Aleksander},
title = {Spectroscopic Identification of Hydrogen Bond Vibrations and Quasi-Isostructural Polymorphism in N-Salicylideneaniline},
journal = {Molecules},
year = {2021},
volume = {26},
number = {16},
pages = {5043},
url = {https://www.mdpi.com/1420-3049/26/16/5043},
doi = {10.3390/molecules26165043}
}
|
| Hetmańczyk Ł, Szklarz P, Kwocz A, Wierzejewska M, Pagacz-Kostrzewa M, Melnikov MY, Tolstoy PM and Filarowski A (2021), "Polymorphism and Conformational Equilibrium of Nitro-Acetophenone in Solid State and under Matrix Conditions", Molecules., May, 2021. Vol. 26(11), pp. 3109. |
| Abstract: Conformational and polymorphic states in the nitro-derivative of o-hydroxy acetophenone have been studied by experimental and theoretical methods. The potential energy curves for the rotation of the nitro group and isomerization of the hydroxyl group have been calculated by density functional theory (DFT) to estimate the barriers of the conformational changes. Two polymorphic forms of the studied compound were obtained by the slow and fast evaporation of polar and non-polar solutions, respectively. Both of the polymorphs were investigated by Infrared-Red (IR) and Raman spectroscopy, Incoherent Inelastic Neutron Scattering (IINS), X-ray diffraction, nuclear quadrupole resonance spectroscopy (NQR), differential scanning calorimetry (DSC) and density functional theory (DFT) methods. In one of the polymorphs, the existence of a phase transition was shown. The position of the nitro group and its impact on the crystal cell of the studied compound were analyzed. The conformational equilibrium determined by the reorientation of the hydroxyl group was observed under argon matrix isolation. An analysis of vibrational spectra was achieved for the interpretation of conformational equilibrium. The infrared spectra were measured in a wide temperature range to reveal the spectral bands that were the most sensitive to the phase transition and conformational equilibrium. The results showed the interrelations between intramolecular processes and macroscopic phenomena in the studied compound. |
BibTeX:
@article{Hetmanczyk2021b,
author = {Hetmańczyk, Łukasz and Szklarz, Przemysław and Kwocz, Agnieszka and Wierzejewska, Maria and Pagacz-Kostrzewa, Magdalena and Melnikov, Mikhail Ya. and Tolstoy, Peter M. and Filarowski, Aleksander},
title = {Polymorphism and Conformational Equilibrium of Nitro-Acetophenone in Solid State and under Matrix Conditions},
journal = {Molecules},
year = {2021},
volume = {26},
number = {11},
pages = {3109},
url = {https://www.mdpi.com/1420-3049/26/11/3109},
doi = {10.3390/molecules26113109}
}
|
| Hoc D and Haznar-Garbacz D (2021), "Foams as unique drug delivery systems", Eur. J. Pharm. Biopharm.. Vol. 167, pp. 73-82. |
| Abstract: Foams are multiphase systems found throughout nature. We meet them equally often in our everyday life, starting with the foam in the morning espresso, where the foam should constitute 10% of the drink or in a glass of beer and ending with the evening bath with foam. These multiphase systems consist mainly of gas, which is separated by liquid or solid lamellae. The lamellae have a very large surface area and a small thickness, which results in their low stability. The foams in pharmaceutics are known for a long time as protective or therapeutic preparations for topical use. However, the physicochemical structure of both solid and liquid foams offers multiple fields of application in the modern therapy. For instance, owing to the unique structure, foams can be also used for parenteral use in the form of implants serving as a drug carrier and at the same time, a scaffold for regenerating the tissue. Foams can also be used orally in the form of controlled drug delivery systems that are potentially useful for sustained or targeted drug delivery. The article describes the unique advantages and features of foams that make them useful in modern pharmacotherapy. |
BibTeX:
@article{Hoc2021,
author = {Hoc, D. and Haznar-Garbacz, D.},
title = {Foams as unique drug delivery systems},
journal = {Eur. J. Pharm. Biopharm.},
year = {2021},
volume = {167},
pages = {73--82},
doi = {10.1016/j.ejpb.2021.07.012}
}
|
| Krzystyniak M, Drużbicki K, Tolnai I and Fabian M (2021), "Local structure and dynamics of tungsten oxide-based glasses: insights from concurrent neutron diffraction and Compton scattering", J. Phys. Commun., Jul, 2021. Vol. 5(7), pp. 075013. |
| Abstract: In this work, following our previous work on molybdate glasses, we employ a combination of neutron diffraction and neutron Compton scattering, augmented by ab initio harmonic lattice dynamics and Reverse Monte Carlo modelling to characterise the force-constant disorder in the tungsten oxide-based glasses. Specifically, we discuss the correlations between the average interatomic force constant magnitudes inferred from neutron Compton scattering and the glass formation ability, measured in terms of the value of the glass transition temperature, as well as the average bond-lengths and interatomic distances obtained from diffraction data analysis. Moreover, we provide a comparative analysis of the widths of force-constant distributions of individual atomic species in glasses and their precursor metal oxides based on the distributions of the widths of nuclear momentum distributions. Furthermore, we assess the degree of softening of atom-projected vibrational densities of states induced by the force-constant disorder in the glasses. |
BibTeX:
@article{Krzystyniak2021,
author = {Krzystyniak, Matthew and Drużbicki, Kacper and Tolnai, Istvan and Fabian, Margit},
title = {Local structure and dynamics of tungsten oxide-based glasses: insights from concurrent neutron diffraction and Compton scattering},
journal = {J. Phys. Commun.},
year = {2021},
volume = {5},
number = {7},
pages = {075013},
url = {https://iopscience.iop.org/article/10.1088/2399-6528/ac1508},
doi = {10.1088/2399-6528/ac1508}
}
|
| Kuzovnikov M, Antonov V, Ivanov A, Hansen T, Savvin S, Kulakov V, Tkacz M and Kolesnikov A (2021), "Neutron scattering study of tantalum monohydride and monodeuteride", Int. J. Hydrogen Energy. Vol. 46(39), pp. 20630-20639. |
| Abstract: Powder samples of TaH0.89 and TaD0.96 are synthesized under a hydrogen (deuterium) pressure of 2.8 GPa and a temperature of 250 °C, then quenched to the liquid nitrogen temperature, recovered to ambient pressure and studied by neutron diffraction (ND) and inelastic neutron scattering (INS). The ND study shows that both hydrogen and deuterium atoms occupy tetrahedral interstitial sites in a distorted body centered cubic (bcc) crystal structure of metal atoms, while the ordering scenarios in TaH0.89 and TaD0.96 are different. Hydrogen and deuterium atoms are ordered in a layered fashion, forming long period superstructures with space groups P4¯ and P222, respectively, so that the unit cells of the crystal structures of TaH0.89 and TaD0.96 are 2×2×7 and 2×2×8 supercells of the initial cubic unit cell. The INS study demonstrates a pronounced “soft” (trumpet-like) anharmonicity of the potential well for H and D atoms. |
BibTeX:
@article{Kuzovnikov2021,
author = {Kuzovnikov, M.A. and Antonov, V.E. and Ivanov, A.S. and Hansen, T. and Savvin, S. and Kulakov, V.I. and Tkacz, M. and Kolesnikov, A.I.},
title = {Neutron scattering study of tantalum monohydride and monodeuteride},
journal = {Int. J. Hydrogen Energy},
year = {2021},
volume = {46},
number = {39},
pages = {20630--20639},
doi = {10.1016/j.ijhydene.2021.03.149}
}
|
| Lalik E, Drużbicki K, Irvine G, Gutmann M, Rudić S, Manuel P, Petříček V and Krzystyniak M (2021), "Interplay between Local Structure and Nuclear Dynamics in Tungstic Acid: A Neutron Scattering Study", J. Phys. Chem. C. Vol. 125(43), pp. 23864-23879. |
| Abstract: We provide an exhaustive characterization of structural properties and nuclear dynamics in tungstic acid (WO3textperiodcenteredH2O). To this end, we employ neutron and X-ray diffraction (ND and XRD) combined with inelastic neutron scattering (INS) and neutron Compton scattering (NCS) experiments, and we corroborate the analysis with extensiveab initiomodeling. The first step in our analysis is the elucidation of the crystal structure based on the refinement of low-temperature powder ND data, extending the knowledge gained from XRD analysis of a mineral specimen of tungstite. These results are confronted with low-temperature INS experiments and zero-temperature phonon calculations. The analysis reveals an inconsistency in the definition of the structure of confined water with respect to crystallographic data, also showing a concomitant failure of the phonon calculations due to a strongly anharmonic confining potential. Extending the computational route towardab initioMD (AIMD) simulations allows us to probe different structural configurations and provides an improved description of the vibrational dynamics as compared to high-resolution INS experiments, nevertheless, requiring the use of effective classical temperatures. The analysis of both INS and the NCS data reveals a remarkable similarity to the nuclear dynamics earlier reported for water confined in single-wall carbon nanotubes (SWNT), which has been qualitatively described as a new phase of ice. Our analysis reveals a strong two-dimensional hydrogen-bonding network, similar to the shell model for water in SWNT. The reported NCS data show narrowing of the hydrogen momentum distribution with respect to the referenceab initiocalculations, indicating a great deal of conformational freedom due to spatial delocalization of protons in the ground state of the system, a clear signature of the quantum character of the nuclei. |
BibTeX:
@article{Lalik2021,
author = {Lalik, E. and Drużbicki, K. and Irvine, G. and Gutmann, M. and Rudić, S. and Manuel, P. and Petříček, V. and Krzystyniak, M.},
title = {Interplay between Local Structure and Nuclear Dynamics in Tungstic Acid: A Neutron Scattering Study},
journal = {J. Phys. Chem. C},
year = {2021},
volume = {125},
number = {43},
pages = {23864--23879},
doi = {10.1021/acs.jpcc.1c05121}
}
|
| Laurell P, Scheie A, Mukherjee CJ, Koza MM, Enderle M, Tylczynski Z, Okamoto S, Coldea R, Tennant DA and Alvarez G (2021), "Quantifying and Controlling Entanglement in the Quantum Magnet", Phys. Rev. Lett., Jul, 2021. Vol. 127(3), pp. 037201. |
| Abstract: The lack of methods to experimentally detect and quantify entanglement in quantum matter impedes our ability to identify materials hosting highly entangled phases, such as quantum spin liquids. We thus investigate the feasibility of using inelastic neutron scattering (INS) to implement a model-independent measurement protocol for entanglement based on three entanglement witnesses: one-tangle, two-tangle, and quantum Fisher information (QFI). We perform high-resolution INS measurements on , a close realization of the transverse-field spin chain, where we can control entanglement using the magnetic field, and compare with density-matrix renormalization group calculations for validation. The three witnesses allow us to infer entanglement properties and make deductions about the quantum state in the material. We find QFI to be a particularly robust experimental probe of entanglement, whereas the one and two-tangles require more careful analysis. Our results lay the foundation for a general entanglement detection protocol for quantum spin systems. |
BibTeX:
@article{Laurell2021,
author = {Laurell, Pontus and Scheie, Allen and Mukherjee, Chiron J. and Koza, Michael M. and Enderle, Mechtild and Tylczynski, Zbigniew and Okamoto, Satoshi and Coldea, Radu and Tennant, D. Alan and Alvarez, Gonzalo},
title = {Quantifying and Controlling Entanglement in the Quantum Magnet},
journal = {Phys. Rev. Lett.},
year = {2021},
volume = {127},
number = {3},
pages = {037201},
url = {https://link.aps.org/doi/10.1103/PhysRevLett.127.037201},
doi = {10.1103/PhysRevLett.127.037201}
}
|
| Matyszewska D, Nazaruk E and Campbell R (2021), "Interactions of anticancer drugs doxorubicin and idarubicin with lipid monolayers: New insight into the composition, structure and morphology", J. Colloid Interface Sci.. Vol. 581, pp. 403-416. |
| Abstract: We quantify directly here for the first time the extents of interactions of two different anthracycline drugs with pure and mixed lipid monolayers with respect to the surface pressure and elucidate differences in the resulting interaction mechanisms. The work concerns interactions of doxorubicin (DOx) and idarubicin (IDA) with monolayers of the zwitterionic DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) and negatively charged DMPS (1,2-dimyristoyl-sn-glycero-3-phospho-L-serine (sodium salt)) as well as a 7:3 mixture of the two lipids. These drugs are used in current cancer treatments, while the lipid systems were chosen as phosphocholines are the major lipid component of healthy cell membranes, and phosphoserines are the major lipid component that is externalized into the outer leaflet of cancerous cell membranes. It is shown that DOx interacts with DMPS monolayers to a greater extent than with DMPC monolayers by lower limits of a factor of 5 at a surface pressure of 10 mN/m and a factor of 12 at 30 mN/m. With increasing surface pressure, the small amount of drug (∼0.3 µmol/m2) bound to DMPC monolayers is excluded from the interface, yet its interaction with DMPS monolayers is enhanced until there is even more drug (∼3.2 µmol/m2) than lipid (∼2.6 µmol/m2) at the interface. Direct evidence is presented for all systems studied that upon surface area compression lipid is reproducibly expelled from the monolayer, which we infer to be in the form of drug-lipid aggregates, yet the nature of adsorption of material back to the monolayer upon expansion is system-dependent. At 30 mN/m, most relevant to human physiology, the interactions of DOx and IDA are starkly different. For DOx, there is a conformational change in the interfacial layer driven by aggregation, resulting in the formation of lateral domains that have extended layers of drug. For the more lipophilic IDA, there is penetration of the drug into the hydrophobic acyl chain region of the monolayer and no indication of lateral segregation. In addition to the Langmuir technique, these advances were made as a result of direct measurements of the interfacial composition, structure and morphology using two different implementations of neutron reflectometry and Brewster angle microscopy. The results provide new insight into key processes that determine the uptake of drugs such as limited drug penetration through cell membranes by passive diffusion as well as activation of drug removal mechanisms related to multidrug resistance. |
BibTeX:
@article{Matyszewska2021,
author = {Matyszewska, D. and Nazaruk, E. and Campbell, R.A.},
title = {Interactions of anticancer drugs doxorubicin and idarubicin with lipid monolayers: New insight into the composition, structure and morphology},
journal = {J. Colloid Interface Sci.},
year = {2021},
volume = {581},
pages = {403--416},
doi = {10.1016/j.jcis.2020.07.092}
}
|
| Minor W, Jaskolski M, Martin S and Dauter Z (2021), "Dr. Alexander Wlodawer—celebrating five decades of service to the structural biology community", FEBS J.. Vol. 288(14), pp. 4160-4164. |
| Abstract: This 75th birthday tribute to our Editorial Board member Alexander Wlodawer recounts his decades-long service to the community of structural biology researchers. His former and current colleagues tell the story of his upbringing and education, followed by an account of his dedication to quality and rigor in crystallography and structural science. The FEBS Journal Editor-in-Chief Seamus Martin further highlights Alex's outstanding contributions to the journal's success over many years. |
BibTeX:
@article{Minor2021,
author = {Minor, W. and Jaskolski, M. and Martin, S.J. and Dauter, Z.},
title = {Dr. Alexander Wlodawer—celebrating five decades of service to the structural biology community},
journal = {FEBS J.},
year = {2021},
volume = {288},
number = {14},
pages = {4160--4164},
doi = {10.1111/febs.16064}
}
|
| Mohn CE, Kryński M, Kob W and Allan NL (2021), "Cooperative excitations in superionic PbF2", Philos. Trans. R. Soc. A Math. Phys. Eng. Sci., Nov, 2021. Vol. 379(2211), pp. 20190455. |
| Abstract: Links between dynamical Frenkel defects and collective diffusion of fluorides in β-PbF 2 are explored using Born-Oppenheimer molecular dynamics. The calculated self-diffusion coefficient and ionic conductivity are 3.2 × 10 -5 cm 2 s -1 and 2.4 Ω -1 cm -1 at 1000 K in excellent agreement with pulsed field gradient and conductivity measurements. The calculated ratio of the tracer-diffusion coefficient and the conductivity-diffusion coefficient (the Haven ratio) is slightly less than unity (about 0.85), which in previous work has been interpreted as providing evidence against collective 'multi-ion' diffusion. By contrast, our molecular dynamics simulations show that fluoride diffusion is highly collective. Analysis of different mechanisms shows a preference for direct collinear 'kick-out' chains where a fluoride enters an occupied tetrahedral hole/cavity and pushes the resident fluoride out of its cavity. Jumps into an occupied cavity leave behind a vacancy, thereby forming dynamic Frenkel defects which trigger a chain of migrating fluorides assisted by local relaxations of the lead ions to accommodate these chains. The calculated lifetime of the Frenkel defects and the collective chains is approximately 1 ps in good agreement with that found from neutron diffraction. This article is part of the Theo Murphy meeting issue 'Understanding fast-ion conduction in solid electrolytes'. |
BibTeX:
@article{Mohn2021,
author = {Mohn, Chris E. and Krynski, Marcin and Kob, Walter and Allan, Neil L.},
title = {Cooperative excitations in superionic PbF2},
journal = {Philos. Trans. R. Soc. A Math. Phys. Eng. Sci.},
year = {2021},
volume = {379},
number = {2211},
pages = {20190455},
url = {https://royalsocietypublishing.org/doi/10.1098/rsta.2019.0455},
doi = {10.1098/rsta.2019.0455}
}
|
| Nabiyev A, Olejniczak A, Islamov A, Pawlukojc A, Ivankov O, Balasoiu M, Zhigunov A, Nuriyev M, Guliyev F, Soloviov D, Ivanshina O and Kuklin A (2021), "Composite Films of HDPE with SiO2 and ZrO2 Nanoparticles: The Structure and Interfacial Effects", Nanomaterials. Vol. 11(10), pp. 2673. |
| Abstract: Herein, we investigated the influence of two types of nanoparticle fillers, i.e., amorphous SiO2 and crystalline ZrO2, on the structural properties of their nanocomposites with high-density polyethylene (HDPE). The composite films were prepared by melt-blending with a filler content that varied from 1% to 20% v/v. The composites were characterized by small-and wide-angle x-ray scattering (SAXS and WAXS), small-angle neutron scattering (SANS), Raman spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). For both fillers, the nanoaggregates were evenly distributed in the polymer matrix and their initial state in the powders determined their surface roughness and fractal character. In the case of the nano-ZrO2 filler, the lamellar thickness and crystallinity degree remain unchanged over a broad range of filler concentrations. SANS and SEM investigation showed poor interfacial adhesion and the presence of voids in the interfacial region. Temperature-programmed SANS investigations showed that at elevated temperatures, these voids become filled due to the flipping motions of polymer chains. The effect was accompanied by a partial aggregation of the filler. For nano-SiO2 filler, the lamellar thickness and the degree of crystallinity increased with increasing the filler loading. SAXS measurements show that the ordering of the lamellae is disrupted even at a filler content of only a few percent. SEM images confirmed good interfacial adhesion and integrity of the SiO2/HDPE composite. This markedly different impact of both fillers on the composite structure is discussed in terms of nanoparticle surface properties and their affinity to the HDPE matrix. |
BibTeX:
@article{Nabiyev2021,
author = {Nabiyev, A.A. and Olejniczak, A. and Islamov, A.Kh. and Pawlukojc, A. and Ivankov, O.I. and Balasoiu, M. and Zhigunov, A. and Nuriyev, M.A. and Guliyev, F.M. and Soloviov, D.V. and Ivanshina, O.Yu. and Kuklin, A.I.},
title = {Composite Films of HDPE with SiO2 and ZrO2 Nanoparticles: The Structure and Interfacial Effects},
journal = {Nanomaterials},
year = {2021},
volume = {11},
number = {10},
pages = {2673},
doi = {10.3390/nano11102673}
}
|
| Nizioł S (2021), "Investigation of the influence of the
aluminium content on the crystallographic and magnetic structures
of the NiFe2-xAlxO4 ferrite by
the neutron diffraction method", In June 16. Vol. 17, pp.
555-560.
[BibTeX] |
BibTeX:
@book{Nizio2021,
author = {Nizioł, S.},
title = {Investigation of the influence of the aluminium content on the crystallographic and magnetic structures of the NiFe2-xAlxO4 ferrite by the neutron diffraction method},
booktitle = {June 16},
year = {2021},
volume = {17},
pages = {555--560}
}
|
| Nygård MM, Fjellvåg ØS, Sørby MH, Sakaki K, Ikeda K, Armstrong J, Vajeeston P, Sławiński WA, Kim H, Machida A, Nakamura Y and Hauback BC (2021), "The average and local structure of TiVCrNbDx (x=0,2.2,8) from total scattering and neutron spectroscopy", Acta Mater., Feb, 2021. Vol. 205, pp. 116496. |
| Abstract: The volumetric hydrogen density of 160 kg H/m3 in TiVCrNbH8 is among the highest for interstitial hydrides, but the reported reversible capacity is only about 2/3 of the full theoretical capacity at room temperature. In the present work we have investigated the local structure in TiVCrNbDx, x=0, 2.2, 8 with the aim to unravel how the remaining sites can be destabilized with respect to hydrogen/deuterium occupation using total scattering measurements and Reverse Monte Carlo (RMC) structure modelling. Our analysis indicates that the partially desorbed deuteride (x=2.2) adopts a body-centred tetragonal structure (I4/mmm) where the deuterium atoms occupy both tetrahedral and octahedral interstices with low occupancies. There is a significantly higher portion of occupied sites with nearest-neighbour metals with low valence-electron concentration VEC. This observation is used to motivate strategies for further destabilization of the hydride. Inelastic neutron scattering (INS) and density functional theory (DFT) calculations indicate that the vibrational density of states is very diverse in TiVCrNbH2.4, and it is suggested that the hydrogen atoms might be mobile between nearby interstices. |
BibTeX:
@article{Nygard2021,
author = {Nygård, Magnus M. and Fjellvåg, Øystein S. and Sørby, Magnus H. and Sakaki, Kouji and Ikeda, Kazutaka and Armstrong, Jeff and Vajeeston, Ponniah and Sławiński, Wojciech A. and Kim, Hyunjeong and Machida, Akihiko and Nakamura, Yumiko and Hauback, Bjørn C.},
title = {The average and local structure of TiVCrNbDx (x=0,2.2,8) from total scattering and neutron spectroscopy},
journal = {Acta Mater.},
year = {2021},
volume = {205},
pages = {116496},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1359645420309216},
doi = {10.1016/j.actamat.2020.116496}
}
|
| Oyeka EE, Winiarski MJ, Błachowski A, Taddei KM, Scheie A and Tran TT (2021), "Potential Skyrmion Host Fe(IO3)3: Connecting Stereoactive Lone-Pair Electron Effects to the Dzyaloshinskii-Moriya Interaction", Chem. Mater., Jun, 2021. Vol. 33(12), pp. 4661-4671. |
| Abstract: Magnetic skyrmions, which are topologically distinct magnetic spin textures, are gaining increased attention for their unique physical properties and potential applications in spintronic devices. Here we present a design strategy for skyrmion host candidates based on combinations of magnetic spin, asymmetric building units having stereoactive lone-pair electrons, and polar lattice symmetry. To demonstrate the viability of the proposed rational design principles, we successfully synthesized a Fe(IO3)3 polycrystalline sample and single crystals by using a new simplified low-Temperature pathway, which is experimentally feasible for extending materials growth of transition metal iodates. Single crystal X-ray and powder synchrotron X-ray diffraction measurements demonstrated that Fe(IO3)3 crystallizes in the polar chiral hexagonal lattice with space group P63. The combined structural features of the macroscopic electric polarization along the c-Axis stemming from the coalignment of the stereoactive lone-pairs of the IO3- trigonal pyramid and the magnetic Fe3+ cation residing on the 3-fold rotation axis were selected to promote asymmetric exchange coupling. We find evidence of a predicted skyrmion phase at 14 K ≤ T ≤ 16 K and 2.5 T ≤ μ0H ≤ 3.2 T driven by a Dzyaloshinskii-Moriya (DM) interaction, a conclusion supported by the appreciable DM exchange and the zero-field spiral antiferromagnetic ground state of Fe(IO3)3 deduced from neutron diffraction experiments. The associated magnetic modulation wavelength of the putative skyrmions is expected to be short â 18 nm, comparable to the period of the DM-driven incommensurate order. This work links stereoactive lone-pair electron effects to enhanced DM interaction, demonstrating a new approach for chemical guidelines in the search for skyrmionic states of matter. |
BibTeX:
@article{Oyeka2021,
author = {Oyeka, Ebube E. and Winiarski, Michał J. and Błachowski, Artur and Taddei, Keith M. and Scheie, Allen and Tran, Thao T.},
title = {Potential Skyrmion Host Fe(IO3)3: Connecting Stereoactive Lone-Pair Electron Effects to the Dzyaloshinskii-Moriya Interaction},
journal = {Chem. Mater.},
year = {2021},
volume = {33},
number = {12},
pages = {4661--4671},
url = {https://pubs.acs.org/doi/10.1021/acs.chemmater.1c01163},
doi = {10.1021/acs.chemmater.1c01163}
}
|
| Oyeka EE, Winiarski MJ, Sorolla M, Taddei KM, Scheie A and Tran TT (2021), "Spin and Orbital Effects on Asymmetric Exchange Interaction in Polar Magnets: M(IO3)2(M = Cu and Mn)", Inorg. Chem.. Vol. 60(21), pp. 16544-16557. |
| Abstract: Magnetic polar materials feature an astonishing range of physical properties, such as magnetoelectric coupling, chiral spin textures, and related new spin topology physics. This is primarily attributable to their lack of space inversion symmetry in conjunction with unpaired electrons, potentially facilitating an asymmetric Dzyaloshinskii-Moriya (DM) exchange interaction supported by spin-orbital and electron-lattice coupling. However, engineering the appropriate ensemble of coupled degrees of freedom necessary for enhanced DM exchange has remained elusive for polar magnets. Here, we study how spin and orbital components influence the capability of promoting the magnetic interaction by studying two magnetic polar materials, α-Cu(IO3)2 (2D) and Mn(IO3)2 (6S), and connecting their electronic and magnetic properties with their structures. The chemically controlled low-temperature synthesis of these complexes resulted in pure polycrystalline samples, providing a viable pathway to prepare bulk forms of transition-metal iodates. Rietveld refinements of the powder synchrotron X-ray diffraction data reveal that these materials exhibit different crystal structures but crystallize in the same polar and chiral P21 space group, giving rise to an electric polarization along the b-axis direction. The presence and absence of an evident phase transition to a possible topologically distinct state observed in α-Cu(IO3)2 and Mn(IO3)2, respectively, imply the important role of spin-orbit coupling. Neutron diffraction experiments reveal helpful insights into the magnetic ground state of these materials. While the long-wavelength incommensurability of α-Cu(IO3)2 is in harmony with sizable asymmetric DM interaction and low dimensionality of the electronic structure, the commensurate stripe AFM ground state of Mn(IO3)2 is attributed to negligible DM exchange and isotropic orbital overlapping. The work demonstrates connections between combined spin and orbital effects, magnetic coupling dimensionality, and DM exchange, providing a worthwhile approach for tuning asymmetric interaction, which promotes evolution of topologically distinct spin phases. |
BibTeX:
@article{Oyeka2021a,
author = {Oyeka, Ebube E. and Winiarski, Michał J. and Sorolla, Maurice and Taddei, Keith M. and Scheie, Allen and Tran, Thao T.},
title = {Spin and Orbital Effects on Asymmetric Exchange Interaction in Polar Magnets: M(IO3)2(M = Cu and Mn)},
journal = {Inorg. Chem.},
year = {2021},
volume = {60},
number = {21},
pages = {16544--16557},
doi = {10.1021/acs.inorgchem.1c02432}
}
|
| Pasturel M, Szlawska M, Ćwik J, Kaczorowski D and Pikul AP (2021), "Antiferromagnetic ordering in the ternary uranium germanide UNi1–xGe2: Neutron diffraction and physical properties studies", Intermetallics., Apr, 2021. Vol. 131, pp. 107112. |
| Abstract: The compound UNi0.45Ge2 was studied by means of X-ray diffraction (XRD), magnetization, neutron diffraction, specific heat and electrical resistivity measurements performed in wide ranges of temperature and magnetic field. The single-crystal XRD experiment indicated that the material crystallizes in the orthorhombic CeNiSi2-type structure with the lattice parameters a = 4.1062(2) Å, b = 15.9272(8) Å and c = 4.0461(2) Å. The physical properties measurements showed that it orders antiferromagnetically at TN = 47 K. The magnetic ordering was confirmed by the neutron diffraction experiment, which revealed that the ordered magnetic moments are aligned along the crystallographic b-axis in a sequence −++−. In strong magnetic fields, a distinct field-induced first-order metamagnetic phase transition occurs, characterized by a large magnetic hysteresis. Temperature and field variations of the electrical resistivity are strongly affected by the atom disorder in the crystallographic unit cell of the investigated compound. |
BibTeX:
@article{Pasturel2021,
author = {Pasturel, Mathieu and Szlawska, Maria and Ćwik, Jacek and Kaczorowski, Dariusz and Pikul, Adam P.},
title = {Antiferromagnetic ordering in the ternary uranium germanide UNi1–Ge2: Neutron diffraction and physical properties studies},
journal = {Intermetallics},
year = {2021},
volume = {131},
pages = {107112},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0966979521000297},
doi = {10.1016/j.intermet.2021.107112}
}
|
| Rudowicz C, Cecot P and Krasowski M (2021), "Selection rules in electron magnetic resonance (EMR) spectroscopy and related techniques: Fundamentals and applications to modern case systems", Phys. B Condens. Matter., May, 2021. Vol. 608, pp. 412863. |
| Abstract: Allowed transitions observed using electron magnetic resonance (EMR) in transition metal (3dN or 4fN) complexes may be predicted by the selection rules. Non-standard selection rules justified by mixing of wavefunctions emerge for nominally forbidden transitions. We present tutorial guide on selection rules in EMR, optical, and inelastic neutron scattering spectroscopy. This includes basic concepts in quantum mechanics and group theory underlying derivations of selection rules and useful rules for nonzero matrix elements. These rules provide crucial information for practitioners. Survey of usage of selection rules in EMR and related studies of novel systems in emerging areas is provided at an introductory level. Applications to modern case systems include: parallel field EMR excitations for integer spin vs half-integer spin ions, nitrogen vacancies in diamond, Haldane gap systems, exchange coupled systems and molecular nanomagnets, and magnetic adatoms on surfaces. Various misconceptions concerning crucial notions, which constitute terminological confusion, have been clarified. |
BibTeX:
@article{Rudowicz2021,
author = {Rudowicz, Czesław and Cecot, Piotr and Krasowski, Mikołaj},
title = {Selection rules in electron magnetic resonance (EMR) spectroscopy and related techniques: Fundamentals and applications to modern case systems},
journal = {Phys. B Condens. Matter},
year = {2021},
volume = {608},
pages = {412863},
url = {https://linkinghub.elsevier.com/retrieve/pii/S092145262100051X},
doi = {10.1016/j.physb.2021.412863}
}
|
| Stelmakh S, Skrobas K, Gierlotka S, Vogel SC and Palosz B (2021), "Atomic structure and grain shape evolution of nanodiamond during annealing in oxidizing atmosphere from neutron diffraction and MD simulations", Diam. Relat. Mater., Jan, 2021. Vol. 111, pp. 108177. |
| Abstract: Real space pair-distribution function (PDF) analysis in conjunction with molecular dynamics (MD) simulations was applied to characterize crystal structure, shape and surface structure of diamond nanoparticles annealed in air up to 880 °C. MD simulated models of individual nanodiamond particles of various shapes and sizes were used to calculate theoretical radial distribution functions G(r) for powders with different grain size distributions. The calculated curves, showing distinct differences for the explored parameter space, were compared to the experimental G(r) functions obtained from neutron scattering for annealed detonated nanodiamond samples in a search for a model best describing the actual powders. It was found that as-synthesized nanodiamond grains are terminated by equally abundant (100), (110) and (111) crystallographic faces and their structure does not change upon annealing in air up to 280 °C. The shape and size of grains annealed above 480 °C changes due to surface etching. The etching rate differs between crystals faces and depends on temperature, resulting in the observed differences in grain shape. Below 680 °C the share of the (110) facets gradually increases and at 680 °C the grains become rhombic dodecahedra terminated solely by (110) surfaces. Further increase of the annealing temperature promotes formation of (111) surfaces and at 880 °C the preferred grain shape becomes an octahedron terminated by a variant of (111) surfaces possessing three dangling sp3 bonds per atom. At lower temperatures all grains become smaller and the size distribution moves towards the lower values. As the annealing temperature increases, the smallest grains disappear entirely and the average grain size grows back. |
BibTeX:
@article{Stelmakh2021,
author = {Stelmakh, Svitlana and Skrobas, Kazimierz and Gierlotka, Stanislaw and Vogel, Sven C. and Palosz, Bogdan},
title = {Atomic structure and grain shape evolution of nanodiamond during annealing in oxidizing atmosphere from neutron diffraction and MD simulations},
journal = {Diam. Relat. Mater.},
year = {2021},
volume = {111},
pages = {108177},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925963520307305},
doi = {10.1016/j.diamond.2020.108177}
}
|
| Topolnicki R and Dopieralski P (2021), "Temperature driven interchange of the effective size of proton with deuterium", Chem. Phys. Lett., Sep, 2021. Vol. 778, pp. 138775. |
| Abstract: We employ ab initio molecular dynamics to study the H/D isotope effect in order to introduce the usually neglected effect of temperature in answering the controversial question: Could deuterium be bigger than protium as suggested from neutron diffraction studies on benzene crystals? Especially that recent neutron powder diffraction study by Fortes and Capelli contradicts previous observations made by Dunitz and Ibberson. Our simulations of the dynamics of isolated benzene and perdeuterated isotopologues have shown surprisingly that, if an environment is not present, the deuterium atom is always larger than the hydrogen atom for temperatures from 100 K up to 1200 K with the rate of change increasing with temperature. Only the inclusion of quantum effects of the nuclei reverses the situation, with hydrogen atoms in isolated benzene becoming larger in volume at low temperatures. In benzene-crystal simulations, we have demonstrated that at some temperatures, above 400 K, deuterium atoms appear bigger than protium atoms. Further studies on the isotope effect and inverse kinetic isotope effect are required from different perspectives; in particular, our results support one of the competing mechanisms of olfaction, in which molecular shape (size) is important in the process. In consequence, the spectral mechanism, which assumes that shape/size of the molecule remains unchanged after deuteration, appears less favorable. |
BibTeX:
@article{Topolnicki2021,
author = {Topolnicki, Rafał and Dopieralski, Przemysław},
title = {Temperature driven interchange of the effective size of proton with deuterium},
journal = {Chem. Phys. Lett.},
year = {2021},
volume = {778},
pages = {138775},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0009261421004589},
doi = {10.1016/j.cplett.2021.138775}
}
|
| Tortora M, Zajdel P, Lowe A, Chorażewski M, Leão J, Jensen G, Bleuel M, Giacomello A, Casciola C, Meloni S, Meloni S and Grosu Y (2021), "Giant Negative Compressibility by Liquid Intrusion into Superhydrophobic Flexible Nanoporous Frameworks", Nano Lett.. Vol. 21(7), pp. 2848-2853. |
| Abstract: Materials or systems demonstrating negative linear compressibility (NLC), whose size increases (decreases) in at least one of their dimensions upon compression (decompression) are very rare. Materials demonstrating this effect in all their dimensions, negative volumetric compressibility (NVC), are exceptional. Here, by liquid porosimetry and in situ neutron diffraction, we show that one can achieve exceptional NLC and NVC values by nonwetting liquid intrusion in flexible porous media, namely in the ZIF-8 metal-organic framework (MOF). Atomistic simulations show that the volumetric expansion is due to the presence of liquid in the windows connecting the cavities of ZIF-8. This discovery paves the way for designing novel materials with exceptional NLC and NVC at reasonable pressures suitable for a wide range of applications. |
BibTeX:
@article{Tortora2021,
author = {Tortora, M. and Zajdel, P. and Lowe, A.R. and Chorażewski, M. and Leão, J.B. and Jensen, G.V. and Bleuel, M. and Giacomello, A. and Casciola, C.M. and Meloni, S. and Meloni, S. and Grosu, Y.},
title = {Giant Negative Compressibility by Liquid Intrusion into Superhydrophobic Flexible Nanoporous Frameworks},
journal = {Nano Lett.},
year = {2021},
volume = {21},
number = {7},
pages = {2848--2853},
doi = {10.1021/acs.nanolett.0c04941}
}
|
| Tsurkan D, Simon P, Schimpf C, Motylenko M, Rafaja D, Roth F, Inosov DS, Makarova AA, Stepniak I, Petrenko I, Springer A, Langer E, Kulbakov AA, Avdeev M, Stefankiewicz AR, Heimler K, Kononchuk O, Hippmann S, Kaiser D, Viehweger C, Rogoll A, Voronkina A, Kovalchuk V, Bazhenov VV, Galli R, Rahimi‐Nasrabadi M, Molodtsov SL, Rahimi P, Falahi S, Joseph Y, Vogt C, Vyalikh DV, Bertau M and Ehrlich H (2021), "Extreme Biomimetics: Designing of the First Nanostructured 3D Spongin–Atacamite Composite and its Application", Adv. Mater., Jul, 2021. Vol. 33(30), pp. 2101682. |
| Abstract: The design of new composite materials using extreme biomimetics is of crucial importance for bioinspired materials science. Further progress in research and application of these new materials is impossible without understanding the mechanisms of formation, as well as structural features at the molecular and nano-level. It presents a challenge to obtain a holistic understanding of the mechanisms underlying the interaction of organic and inorganic phases under conditions of harsh chemical reactions for biopolymers. Yet, an understanding of these mechanisms can lead to the development of unusual—but functional—hybrid materials. In this work, a key way of designing centimeter-scale macroporous 3D composites, using renewable marine biopolymer spongin and a model industrial solution that simulates the highly toxic copper-containing waste generated in the production of printed circuit boards worldwide, is proposed. A new spongin–atacamite composite material is developed and its structure is confirmed using neutron diffraction, X-ray diffraction, high-resolution transmission electron microscopy/selected-area electron diffraction, X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy, and electron paramagnetic resonance spectroscopy. The formation mechanism for this material is also proposed. This study provides experimental evidence suggesting multifunctional applicability of the designed composite in the development of 3D constructed sensors, catalysts, and antibacterial filter systems. |
BibTeX:
@article{Tsurkan2021,
author = {Tsurkan, Dmitry and Simon, Paul and Schimpf, Christian and Motylenko, Mykhaylo and Rafaja, David and Roth, Friedrich and Inosov, Dmytro S. and Makarova, Anna A. and Stepniak, Izabela and Petrenko, Iaroslav and Springer, Armin and Langer, Enrico and Kulbakov, Anton A. and Avdeev, Maxim and Stefankiewicz, Artur R. and Heimler, Korbinian and Kononchuk, Olga and Hippmann, Sebastian and Kaiser, Doreen and Viehweger, Christine and Rogoll, Anika and Voronkina, Alona and Kovalchuk, Valentine and Bazhenov, Vasilii V. and Galli, Roberta and Rahimi‐Nasrabadi, Mehdi and Molodtsov, Serguei L. and Rahimi, Parvaneh and Falahi, Sedigheh and Joseph, Yvonne and Vogt, Carla and Vyalikh, Denis V. and Bertau, Martin and Ehrlich, Hermann},
title = {Extreme Biomimetics: Designing of the First Nanostructured 3D Spongin–Atacamite Composite and its Application},
journal = {Adv. Mater.},
year = {2021},
volume = {33},
number = {30},
pages = {2101682},
url = {https://onlinelibrary.wiley.com/doi/10.1002/adma.202101682},
doi = {10.1002/adma.202101682}
}
|
| Vázquez-Fernández I, Drużbicki K, Fernandez-Alonso F, Mukhopadhyay S, Nockemann P, Parker S, Rudić S, Stana S-M, Tomkinson J, Yeadon D, Seddon K and Plechkova N (2021), "Spectroscopic Signatures of Hydrogen-Bonding Motifs in Protonic Ionic Liquid Systems: Insights from Diethylammonium Nitrate in the Solid State", J. Phys. Chem. C. Vol. 125(44), pp. 24463-24476. |
| Abstract: Diethylammonium nitrate, [N0 0 2 2][NO3], and its perdeuterated analogue, [ND D 2 2] [NO3], were structurally characterized and studied by infrared, Raman, and inelastic neutron scattering (INS) spectroscopy. Using these experimental data along with state-of-the-art computational materials modeling, we report unambiguous spectroscopic signatures of hydrogen-bonding interactions between the two counterions. An exhaustive assignment of the spectral features observed with each technique has been provided, and a number of distinct modes related to NHtextperiodcenteredtextperiodcenteredtextperiodcenteredO dynamics have been identified. We put a particular emphasis on a detailed interpretation of the high-resolution, broadband INS experiments. In particular, the INS data highlight the importance of conformational degrees of freedom within the alkyl chains, a ubiquitous feature of ionic liquid (IL) systems. These findings also enable an in-depth physicochemical understanding of protonic IL systems, a first and necessary step to the tailoring of hydrogen-bonding networks in this important class of materials. |
BibTeX:
@article{Vazquez-Fernandez2021,
author = {Vázquez-Fernández, I. and Drużbicki, K. and Fernandez-Alonso, F. and Mukhopadhyay, S. and Nockemann, P. and Parker, S.F. and Rudić, S. and Stana, S.-M. and Tomkinson, J. and Yeadon, D.J. and Seddon, K.R. and Plechkova, N.V.},
title = {Spectroscopic Signatures of Hydrogen-Bonding Motifs in Protonic Ionic Liquid Systems: Insights from Diethylammonium Nitrate in the Solid State},
journal = {J. Phys. Chem. C},
year = {2021},
volume = {125},
number = {44},
pages = {24463--24476},
doi = {10.1021/acs.jpcc.1c05137}
}
|
| Wanat M, Malinska M, Gutmann M, Cooper R and Wozniak K (2021), "HAR, TAAM and BODD refinements of model crystal structures using Cu Kα and Mo Kα X-ray diffraction data", Acta Crystallogr. Sect. B Struct. Sci. Cryst. Eng. Mater.. Vol. 77, pp. 41-53. |
| Abstract: The Independent Atom Model (IAM) of electron density is used in routine X-ray data analysis. However, this model does not give a quantitative description of the electron-density distribution. A better model that allows for modelling of aspherical charge density deformations is introduced by the Hansen-Coppens variant of the multipole model of electron density. However, the application of this model requires crystals of excellent quality and high-resolution XRD data which are quite often difficult criteria to fulfil. Therefore, Mo Kα and Cu Kα data of three model compounds (tricyclic imide, xylitol and methyluracil) were refined using IAM and new methods which enabled the refinement and reconstruction of charge density based on the Cu Kα data. These methods were the Bond-Oriented Deformation Density (BODD) model, Hirshfeld Atom Refinement (HAR) and the Transferable Aspherical Atom Model (TAAM). The final results were compared to the model obtained from neutron diffraction experiments. Our results demonstrated not only that Cu Kα data may be refined using BODD, HAR and TAAM methods, but also revealed systematic errors arising from the use of Cu Kα data. These errors were a result of the limited information in the low-resolution data set that manifested as higher values for the anisotropic displacement parameters (ADPs) and smaller maxima and minima of the residual electron density for the Cu Kα data compared to the Mo Kα data. Notably, these systematic errors were much less significant than those found for the IAM. Therefore, the application of BODD, HAR and TAAM on Cu Kα data has a more significant influence on the final results of refinement than for the Mo Kα data. |
BibTeX:
@article{Wanat2021,
author = {Wanat, M. and Malinska, M. and Gutmann, M.J. and Cooper, R.I. and Wozniak, K.},
title = {HAR, TAAM and BODD refinements of model crystal structures using Cu Kα and Mo Kα X-ray diffraction data},
journal = {Acta Crystallogr. Sect. B Struct. Sci. Cryst. Eng. Mater.},
year = {2021},
volume = {77},
pages = {41--53},
doi = {10.1107/S2052520620014936}
}
|
| Witek M, Krzystyniak M, Romanelli G and Witczak T (2021), "Glass Transition in Rice Pasta as Observed by Combined Neutron Scattering and Time-Domain NMR", Polymers (Basel)., Jul, 2021. Vol. 13(15), pp. 2426. |
| Abstract: Experimental protocols aiming at the characterisation of glass transition often suffer from ambiguity. The ambition of the present study is to describe the glass transition in a complex, micro heterogeneous system, the dry rice pasta, in a most unambiguous manner, minimising the influence of technique-specific bias. To this end, we apply an unprecedented combination of experimental techniques. Apart from the usually used NMR and DSC, we employ, in a concurrent manner, neutron transmission, diffraction, and Compton scattering. This enables us to investigate the glass transition over a range of spatio-temporal scales that stretches over seven orders of magnitude. The results obtained by neutron diffraction and DSC reveal that dry rice pasta is almost entirely amorphous. Moreover, the glass transition is evidenced by neutron transmission and diffraction data and manifested as a significant decrease of the average sample number density in the temperature range between 40 and 60 °C. At the microscopic level, our NMR, neutron transmission and Compton scattering results provide evidence of changes in the secondary structure of the starch within the dry rice pasta accompanying the glass transition, whereby the long-range order provided by the polymer structure within the starch present in the dry rice pasta is partially lost. |
BibTeX:
@article{Witek2021,
author = {Witek, Magdalena and Krzystyniak, Maciej and Romanelli, Giovanni and Witczak, Teresa},
title = {Glass Transition in Rice Pasta as Observed by Combined Neutron Scattering and Time-Domain NMR},
journal = {Polymers (Basel).},
year = {2021},
volume = {13},
number = {15},
pages = {2426},
url = {https://www.mdpi.com/2073-4360/13/15/2426},
doi = {10.3390/polym13152426}
}
|
| Woińska M, Chodkiewicz M and Woźniak K (2021), "Towards accurate and precise positions of hydrogen atoms bonded to heavy metal atoms", Chem. Commun.. Vol. 57(30), pp. 3652-3655. |
| Abstract: A comparison of five X-ray structures of transition-metal-bound hydride complexes, successfully refined using Hirshfeld Atom Refinement (HAR) against low resolution X-ray diffraction data (including the positions and ADPs of all hydrogen atoms), with neutron structures shows that using aspherical atomic scattering factors instead of spherical ones results in systematic elongation of metal-hydrogen bonds, which in the case of the highest-quality data leads to excellent agreement of the X-ray and the neutron-derived bond lengths. |
BibTeX:
@article{Woinska2021,
author = {Woińska, M. and Chodkiewicz, M.L. and Woźniak, K.},
title = {Towards accurate and precise positions of hydrogen atoms bonded to heavy metal atoms},
journal = {Chem. Commun.},
year = {2021},
volume = {57},
number = {30},
pages = {3652--3655},
doi = {10.1039/d0cc07661a}
}
|
| Wojciechowski K, Jurek I, Góral I, Campana M, Geue T and Gutberlet T (2021), "Surface-active extracts from plants rich in saponins – effect on lipid mono- and bilayers", Surfaces and Interfaces., Dec, 2021. Vol. 27, pp. 101486. |
| Abstract: The aqueous extracts of the seeds of oat (Avena sativa L.), horse chestnut (Aesculus hippocastanum L.), soybean (Glycine max L.), cowherb (Vaccaria hispanica [P. Mill.] Rauschert) and quinoa (Chenopodium quinoa Willd.), and the roots of soapwort (Saponaria officinalis L.) without any preservatives were characterized in terms of their surface tension, surface compression (dilational) rheology, foamability and foam stability. The saponin content in the extracts was determined using UPLC-MS and their interaction with model lipid monolayers consisting of dipalmitoylphosphatidylcholine (DPPC)/cholesterol and Ceramide AP/stearic acid/cholesterol were analyzed by surface pressure relaxation, surface compression elasticity and neutron reflectometry (NR). The lipid composition was chosen to mimic the cell membrane of keratinocytes – major constituents of the human deeper skin layers, and the intercellular lipids (“mortar”) in the “bricks and mortar” model of the outermost layer of the epidermis (stratum corneum). Bilayers of DPPC/cholesterol were additionally characterized using dynamic light scattering (DLS) and NR. The oat and soybean extracts were shown to be much less abundant in saponins as compared to cowherb, horse chestnut, soapwort or quinoa, and showed limited foaming abilities. They did not affect significantly the model lipid mono- and bilayers mimicking the skin outer layers, either. The horse chestnut extract affected both model membranes to the highest extent, yet without solubilizing the lipids. |
BibTeX:
@article{Wojciechowski2021,
author = {Wojciechowski, Kamil and Jurek, Ilona and Góral, Ilona and Campana, Mario and Geue, Thomas and Gutberlet, Thomas},
title = {Surface-active extracts from plants rich in saponins – effect on lipid mono- and bilayers},
journal = {Surfaces and Interfaces},
year = {2021},
volume = {27},
pages = {101486},
url = {https://linkinghub.elsevier.com/retrieve/pii/S2468023021005630},
doi = {10.1016/j.surfin.2021.101486}
}
|
| Zajdel P, Chorażewski M, Leão J, Jensen G, Bleuel M, Zhang H-F, Feng T, Luo D, Li M, Lowe A, Li D and Grosu Y (2021), "Inflation Negative Compressibility during Intrusion-Extrusion of a Non-Wetting Liquid into a Flexible Nanoporous Framework", J. Phys. Chem. Lett.. Vol. 12(20), pp. 4951-4957. |
| Abstract: Negative compressibility (NC) is a phenomenon when an object expands/shrinks in at least one of its dimensions upon compression/decompression. NC is very rare and is of great interest for a number of applications. In this work a gigantic (more than one order of magnitude higher compared to the reported values) NC effect was recorded during intrusion-extrusion of a non-wetting liquid into a flexible porous structure. For this purpose, in situ high-pressure neutron scattering, intrusion-extrusion experiments, and DFT calculations were applied to a system consisting of water and a highly hydrophobic Cu2(tebpz) metal-organic framework (MOF), which upon water penetration expands in a and c directions to demonstrate NC coefficients more than order of magnitude higher compared to the highest values ever reported. The proposed approach is not limited to the materials used in this work and can be applied to achieve coefficients of negative linear compressibility of more than 103 TPa-1. |
BibTeX:
@article{Zajdel2021,
author = {Zajdel, P. and Chorażewski, M. and Leão, J.B. and Jensen, G.V. and Bleuel, M. and Zhang, H.-F. and Feng, T. and Luo, D. and Li, M. and Lowe, A.R. and Li, D. and Grosu, Y.},
title = {Inflation Negative Compressibility during Intrusion-Extrusion of a Non-Wetting Liquid into a Flexible Nanoporous Framework},
journal = {J. Phys. Chem. Lett.},
year = {2021},
volume = {12},
number = {20},
pages = {4951--4957},
doi = {10.1021/acs.jpclett.1c01305}
}
|
| Babilas R, Młynarek K, Łoński W, Łukowiec D, Kadziołka-Gaweł M, Czeppe T and Temleitner L (2020), "Structural Characterization of Al65Cu20Fe15 Melt-Spun Alloy by X-ray, Neutron Diffraction, High-Resolution Electron Microscopy and Mössbauer Spectroscopy", Materials (Basel)., Dec, 2020. Vol. 14(1), pp. 54. |
| Abstract: The aim of the work was to characterize the structure of Al65Cu20Fe15 alloy obtained with the use of conventional casting and rapid solidification-melt-spinning technology. Based on the literature data, the possibility of an icosahedral quasicrystalline phase forming in the Al-Cu-Fe was verified. Structure analysis was performed based on the results of X-ray diffraction, neutron diffraction, 57Fe Mössbauer and transmission electron microscopy. Studies using differential scanning calorimetry were carried out to describe the crystallization mechanism. Additionally, electrochemical tests were performed in order to characterize the influence of the structure and cooling rate on the corrosion resistance. On the basis of the structural studies, the formation of a metastable icosahedral phase and partial amorphous state of ribbon structure were demonstrated. The possibility of the formation of icosahedral quasicrystalline phase I-AlCuFe together with the crystalline phases was indicated by X-ray diffraction (XRD), neutron diffraction (ND) patterns, Mössbauer spectroscopy, high-resolution transmission electron microscopy (HRTEM) observations and differential scanning calorimetry (DSC) curves. The beneficial effect of the application of rapid solidification on the corrosive properties was also confirmed. |
BibTeX:
@article{Babilas2021,
author = {Babilas, Rafał and Młynarek, Katarzyna and Łoński, Wojciech and Łukowiec, Dariusz and Kadziołka-Gaweł, Mariola and Czeppe, Tomasz and Temleitner, László},
title = {Structural Characterization of Al65Cu20Fe15 Melt-Spun Alloy by X-ray, Neutron Diffraction, High-Resolution Electron Microscopy and Mössbauer Spectroscopy},
journal = {Materials (Basel).},
year = {2020},
volume = {14},
number = {1},
pages = {54},
url = {https://www.mdpi.com/1996-1944/14/1/54},
doi = {10.3390/ma14010054}
}
|
| Baran S, Kurzydło P, Tyvanchuk Y, Hoser A and Szytuła A (2020), "Magnetic properties and magnetic structures in R3Ni2In4 (R = Tb–Tm)", J. Alloys Compd., Aug, 2020. Vol. 832, pp. 154926. |
| Abstract: The R3Ni2In4 (R = Tb–Tm) ternary indides have been investigated by X-ray and neutron powder diffraction as well as magnetometric measurements. The compounds crystallize in the hexagonal Lu3Co2In4-type structure (a lower-symmetry derivative of the ZrNiAl-type one). Er3Ni2In4 has been found paramagnetic down to 1.6 K while all other samples order antiferromagnetically below 23.3 K (R = Tb), 9.7 K (R = Dy), 3.3 K (R = Ho) and 3.2 K (R = Tm). The magnetic unit cell in R3Ni2In4 (R = Tb, Dy) is doubled along the c-axis with respect to the crystal one (propagation vector k→=[0,0,1/2]). The magnetic moments lie in the basal plane and form a “triangular” magnetic structure as often found in geometrically frustrated antiferromagnets. The magnetic order in Ho3Ni2In4 consists of two components: a commensurate one which is described above (k→=[0,0,1/2]) and an incommensurate one (k→=[1/3,1/3,kz] where kz=0.271(11) at 1.6 K). The magnetic moments of the incommensurate component are inclined at a small angle with respect to the basal plane and form a non-collinear magnetic structure. The magnetic structure in Tm3Ni2In4 is a commensurate one (k→=[1/3,13,1/2]) with magnetic moments within the basal plane forming a non-collinear “triangular” structure. A determination of magnetic structures is supported by detailed symmetry analysis. |
BibTeX:
@article{Baran2020,
author = {Baran, S. and Kurzydło, P. and Tyvanchuk, Yu. and Hoser, A. and Szytuła, A.},
title = {Magnetic properties and magnetic structures in R3Ni2In4 (R = Tb–Tm)},
journal = {J. Alloys Compd.},
year = {2020},
volume = {832},
pages = {154926},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838820312895},
doi = {10.1016/j.jallcom.2020.154926}
}
|
| Baran S, Tyvanchuk Y, Penc B, Kalychak Y, Hoser A and Szytuła A (2020), "Crystal structure and complex magnetic properties of R11Pd4In9 compounds (R = Y, Gd–Er)", Intermetallics., Aug, 2020. Vol. 123, pp. 106837. |
| Abstract: Magnetic properties of the R11Pd4In9 compounds (R = Y, Gd–Er) were investigated by means of X-ray diffraction and magnetic measurements. Three of these compounds, namely those with R = Y, Ho and Er, are newly synthesized. The compounds crystallize in the orthorhombic Nd11Pd4In9-type crystal structure (oC48, Cmmm) in which the rare earth atoms occupy five nonequivalent sublattices. Magnetic properties of the investigated compounds are related mainly to the R3+ ions, except the case of Y11Pd4In9 which is a Pauli paramagnet. For R = Gd-Er, the values of effective magnetic moments in the paramagnetic state are close to the free R3+ ion values while the moments in the ordered state at T = 2 K and H = 90 kOe are lower than the respective R3+ moments. The compounds have complex magnetic properties. All paramagnetic Curie temperatures are positive suggesting that the ferromagnetic interactions are predominant. However, the low temperature data indicate an antiferromagnetic order. With increase of temperature the magnetic properties change from antiferro-to ferrimagnetic and finally to paramagnetic ones. The critical temperatures of magnetic ordering do not fulfill the de Gennes scaling, indicating a crystalline electric field contribution to stabilization of the magnetic order at low temperatures. The neutron diffraction measurements, performed for Ho11Pd4In9, reveal a coexistence of two magnetic phases at low temperatures: the antiferromagnetic with propagation vector k = [0,0,½] and the ferrimagnetic one with k = [0,0,0]. The antiferromagnetic order is predominant at low temperatures while the ferrimagnetic one dominates at intermediate temperatures. |
BibTeX:
@article{Baran2020a,
author = {Baran, S. and Tyvanchuk, Yu. and Penc, B. and Kalychak, Ya. and Hoser, A. and Szytuła, A.},
title = {Crystal structure and complex magnetic properties of R11Pd4In9 compounds (R = Y, Gd–Er)},
journal = {Intermetallics},
year = {2020},
volume = {123},
pages = {106837},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0966979520303095},
doi = {10.1016/j.intermet.2020.106837}
}
|
| Bernal FL, Gonano B, Lundvall F, Wragg DS, Fjellv+Ñg H, Veillon F, Séawiäski WA and Fjellvng ŸS (2020), "Canted antiferromagnetism in high-purity NaFeF3 prepared by a novel wet-chemical synthesis method", Phys. Rev. Mater., Nov, 2020. Vol. 4(11), pp. 114412. |
| Abstract: We report a synthesis method, and structural and magnetic characterization, for the fluoroperovskite NaFeF3. We have developed a wet-chemical method that allows preparation of large volumes of air-sensitive fluoroperovskites with high purity. NaFeF3 has a N+¬el temperature (TN) of 90 K and a Weiss constant (++) of -124 K, corresponding to dominant antiferromagnetic interactions. Below TN, a slight difference is observed between zero-field and field-cooled samples, indicating spin canting and weak ferromagnetism. AC magnetometry supports that weak ferromagnetism is inherent to NaFeF3 and not due to an impurity. From powder neutron diffraction data, we describe the magnetic structure precisely as a weakly canted G-type (magnetic space group PnGǦmaGǦ). A ferromagnetic component is allowed in PnGǦmaGǦ, however, this component is too small to be confirmed on the basis of powder neutron diffraction data and may be absent in zero magnetic fields. |
BibTeX:
@article{Bernal2020,
author = {Bernal, Fabian L.M. and Gonano, Bruno and Lundvall, Fredrik and Wragg, David S. and Fjellv+Ñg, Helmer and Veillon, Fabien and Séawiäski, Wojciech A. and Fjellvng, Ÿystein S.},
title = {Canted antiferromagnetism in high-purity NaFeF3 prepared by a novel wet-chemical synthesis method},
journal = {Phys. Rev. Mater.},
year = {2020},
volume = {4},
number = {11},
pages = {114412},
url = {https://link.aps.org/doi/10.1103/PhysRevMaterials.4.114412},
doi = {10.1103/PhysRevMaterials.4.114412}
}
|
| Bernal FL, Sottmann J, Wragg DS, Fjellvåg H, Fjellvåg ØS, Drathen C, Sławiński WA and Løvvik OM (2020), "Structural and magnetic characterization of the elusive Jahn-Teller active NaCrF3", Phys. Rev. Mater., May, 2020. Vol. 4(5), pp. 054412. |
| Abstract: We report on the structural and magnetic properties of the elusive Jahn-Teller active compound NaCrF3, for first time synthesized in large quantities allowing detailed characterization. The crystal structure of NaCrF3 is initially described from a DFT model, which helped serve as the basis for indexing and structure determination confirmed by high-resolution synchrotron x-ray diffraction experiments. NaCrF3 adopts the triclinic space group P1¯ (isostructural with NaCuF3). Magnetometry studies at low temperature show that NaCrF3 is a weak antiferromagnet, Weiss temperature θ=-4 K. The Néel temperature is TN=21.3 K and the paramagnetic moment μ=4.47μB is in accordance with the theoretical S=2. Field-dependent measurements between 2 and 12 K unveil the onset of metamagnetic behavior. Our experiments revealed a weakly canted A-type magnetic structure observed by neutron powder diffraction, with a magnetic propagation vector (1/2,1/2,0) and a magnetic moment of 3.51μB at 1.5 K. Our results shed further light on the Jahn-Teller effects and strong correlations as a function of A-ion size in the family ACrF3. |
BibTeX:
@article{Bernal2020a,
author = {Bernal, Fabian L.M. and Sottmann, Jonas and Wragg, David S. and Fjellvåg, Helmer and Fjellvåg, Øystein S. and Drathen, Christina and Sławiński, Wojciech A. and Løvvik, Ole Martin},
title = {Structural and magnetic characterization of the elusive Jahn-Teller active NaCrF3},
journal = {Phys. Rev. Mater.},
year = {2020},
volume = {4},
number = {5},
pages = {054412},
url = {https://link.aps.org/doi/10.1103/PhysRevMaterials.4.054412},
doi = {10.1103/PhysRevMaterials.4.054412}
}
|
| Borgschulte A, Terreni J, Billeter E, Daemen L, Cheng Y, Pandey A, Łodziana Z, Hemley RJ and Ramirez-Cuesta AJ (2020), "Inelastic neutron scattering evidence for anomalous H–H distances in metal hydrides", Proc. Natl. Acad. Sci., Feb, 2020. Vol. 117(8), pp. 4021-4026. |
| Abstract: Hydrogen in metals alters the electronic structure of such materials and hence modifies the physical and chemical properties. In conventional transition metal hydrides containing atomic hydrogen, the minimum hydrogen–hydrogen distances are around 2.1 Å under ambient conditions (Switendick criterion). Although hints of H–H distances below 2.1 Å in A B 2 alloys have been reported, evidence is inconclusive as hydrogen positions are difficult to locate by diffraction techniques. Here, inelastic neutron scattering is used as a local probe of the hydrogen interactions together with electronic structure modeling of a well-studied and prototypical metal hydride Z r V 2 H x . The results provide evidence for anomalous hydrogen–hydrogen distances as short as 1.6 Å. The findings provide insights leading to the creation of materials with properties such as very high T c superconductivity and other quantum behaviors. |
BibTeX:
@article{Borgschulte2020,
author = {Borgschulte, Andreas and Terreni, Jasmin and Billeter, Emanuel and Daemen, Luke and Cheng, Yongqiang and Pandey, Anup and Łodziana, Zbigniew and Hemley, Russell J. and Ramirez-Cuesta, Anibal J.},
title = {Inelastic neutron scattering evidence for anomalous H–H distances in metal hydrides},
journal = {Proc. Natl. Acad. Sci.},
year = {2020},
volume = {117},
number = {8},
pages = {4021--4026},
url = {https://pnas.org/doi/full/10.1073/pnas.1912900117},
doi = {10.1073/pnas.1912900117}
}
|
| Borowska-Centkowska A, Leszczynska M, Wrobel W, Malys M, Hull S, Krok F and Abrahams I (2020), "Stability of tungsten-doped δ-Bi3YO6", Solid State Ionics., Feb, 2020. Vol. 345, pp. 115173. |
| Abstract: The stability of bismuth yttrium oxide doped with tungsten, Bi3Y1−xWxO6+3x/2, on annealing in air for up to 1000 h at 650 °C was investigated using a.c. impedance spectroscopy and neutron diffraction. Compositions up to x = 0.2 all show some degree of conductivity decay, but only in the case of the x = 0.10 composition is this decay relatively small and not associated with a significant structural change. Details of the short range structure of this composition were investigated by reverse Monte Carlo modelling of total neutron scattering data and again reveal no significant changes prior to and post annealing. A preference for 〈100〉 oxide ion vacancy pair alignment is found in the structure, consistent with models for oxide ion conduction in these systems. Additionally, the total scattering analysis reveals a preferred vacancy association with the W6+ cations, which adopt a four coordinate geometry in this system. |
BibTeX:
@article{Borowska-Centkowska2020,
author = {Borowska-Centkowska, A. and Leszczynska, M. and Wrobel, W. and Malys, M. and Hull, S. and Krok, F. and Abrahams, I.},
title = {Stability of tungsten-doped δ-Bi3YO6},
journal = {Solid State Ionics},
year = {2020},
volume = {345},
pages = {115173},
url = {https://linkinghub.elsevier.com/retrieve/pii/S016727381930863X},
doi = {10.1016/j.ssi.2019.115173}
}
|
| Chen Y, Chuang YW, Lee SH, Zhu Y, Honz K, Guan Y, Wang Y, Wang K, Mao Z, Zhu J, Heikes C, Quarterman P, Zajdel P, Borchers JA and Ratcliff W (2020), "Ferromagnetism in van der Waals compound MnS b1.8 B i0.2 T e4", Phys. Rev. Mater., Jun, 2020. Vol. 4(6), pp. 064411. |
| Abstract: The intersection of topology and magnetism represents a new playground to discover novel quantum phenomena and device concepts. In this work, we show that under certain synthetic conditions, a van der Waals single-crystalline compound MnSb1.8Bi0.2Te4 exhibits a net ferromagnetic state with a Curie temperature of 26 K, in contrast to the fully compensated antiferromagnetic order observed previously for other members of the Mn(Sb,Bi)2Te4 family. We employ magneto-transport, bulk magnetization, x-ray and neutron scattering studies to illustrate the structural, magnetic, and electrical properties of MnSb1.8Bi0.2Te4. Our structural analyses reveal considerable Mn-Sb site mixing and suggest a recently proposed mechanism, where Mn occupying the Sb site mediates a ferromagnetic coupling between Mn layers [Murakami, Phys. Rev. B 100, 195103 (2019)10.1103/PhysRevB.100.195103], could be at play. Close comparisons made to an antiferromagnetic compound MnSb2Te4 illustrate the subtle magnetic interactions of the system and the important role played by local chemistry. The appearance of an unusual anomalous Hall effect in MnSb1.8Bi0.2Te4 at low temperatures hints at a magnetic ground state different from other members of this family. Our results are an important step in the synthesis and understanding of magnetism in materials with topological characteristics. |
BibTeX:
@article{Chen2020,
author = {Chen, Yangyang and Chuang, Ya Wen and Lee, Seng Huat and Zhu, Yanglin and Honz, Kevin and Guan, Yingdong and Wang, Yu and Wang, Ke and Mao, Zhiqiang and Zhu, Jun and Heikes, Colin and Quarterman, P. and Zajdel, Pawel and Borchers, Julie A. and Ratcliff, William},
title = {Ferromagnetism in van der Waals compound MnS b1.8 B i0.2 T e4},
journal = {Phys. Rev. Mater.},
year = {2020},
volume = {4},
number = {6},
pages = {064411},
url = {https://link.aps.org/doi/10.1103/PhysRevMaterials.4.064411},
doi = {10.1103/PhysRevMaterials.4.064411}
}
|
| Chodkiewicz M, Woińska M and Woźniak K (2020), "Hirshfeld atom like refinement with alternative electron density partitions", IUCrJ. Vol. 7, pp. 1199-1215. |
| Abstract: Hirshfeld atom refinement is one of the most successful methods for the accurate determination of structural parameters for hydrogen atoms from X-ray diffraction data. This work introduces a generalization of the method [generalized atom refinement (GAR)], consisting of the application of various methods of partitioning electron density into atomic contributions. These were tested on three organic structures using the following partitions: Hirshfeld, iterative Hirshfeld, iterative stockholder, minimal basis iterative stockholder and Becke. The effects of partition choice were also compared with those caused by other factors such as quantum chemical methodology, basis set, representation of the crystal field and a combination of these factors. The differences between the partitions were small in terms of R factor (e.g. much smaller than for refinements with different quantum chemistry methods, i.e. Hartree-Fock and coupled cluster) and therefore no single partition was clearly the best in terms of experimental data reconstruction. In the case of structural parameters the differences between the partitions are comparable to those related to the choice of other factors. We have observed the systematic effects of the partition choice on bond lengths and ADP values of polar hydrogen atoms. The bond lengths were also systematically influenced by the choice of electron density calculation methodology. This suggests that GAR-derived structural parameters could be systematically improved by selecting an optimal combination of the partition and quantum chemistry method. The results of the refinements were compared with those of neutron diffraction experiments. This allowed a selection of the most promising partition methods for further optimization of GAR settings, namely the Hirshfeld, iterative stockholder and minimal basis iterative stockholder. |
BibTeX:
@article{Chodkiewicz2020,
author = {Chodkiewicz, M.L. and Woińska, M. and Woźniak, K.},
title = {Hirshfeld atom like refinement with alternative electron density partitions},
journal = {IUCrJ},
year = {2020},
volume = {7},
pages = {1199--1215},
doi = {10.1107/S2052252520013603}
}
|
| Czub J, Shtender VV, Przewoźnik J, Zarzecka A, Hoser A and Gondek (2020), "On the properties of the novel CeMgNi2T2 (T = Co, Cu) alloys and their hydrides", J. Alloys Compd., Jan, 2020. Vol. 814, pp. 152244. |
| Abstract: In this contribution, we report the results of the studies on the novel CeMgNi2Co2 and CeMgNi2Cu2 alloys and their hydrides/deuterides. Both the parent alloys and the CeMgNi2Co2H6.1 hydride crystallize in the MgCu4Sn-type structure, while the CeMgNi2Cu2H6.0 hydride becomes almost completely amorphous. In the MgCu4Sn structure the 3d metals are distributed over the 16e site forming the pyrochlore lattice. That makes this system particularly interesting as concerns the magnetic properties. Our studies reveal that magnetic susceptibilities of the alloys are weakly temperature-dependent and therefore, the Pauli-like paramagnetism can be suggested. Additionally, the results of the low temperature neutron diffraction experiments revealed the lack of the long-range magnetic ordering. |
BibTeX:
@article{Czub2020,
author = {Czub, J. and Shtender, V. V. and Przewoźnik, J. and Zarzecka, A. and Hoser, A. and Gondek},
title = {On the properties of the novel CeMgNi2T2 (T = Co, Cu) alloys and their hydrides},
journal = {J. Alloys Compd.},
year = {2020},
volume = {814},
pages = {152244},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838819334905},
doi = {10.1016/j.jallcom.2019.152244}
}
|
| Fabiola Sanjuan-Szklarz W, Woińska M, Domagala S, Dominiak PM, Grabowsky S, Jayatilaka D, Gutmann M and Woźniak K (2020), "On the accuracy and precision of X-ray and neutron diffraction results as a function of resolution and the electron density model", IUCrJ., Sep, 2020. Vol. 7(5), pp. 920-933. |
| Abstract: X-ray diffraction is the main source of three-dimensional structural information. In total, more than 1.5 million crystal structures have been refined and deposited in structural databanks (PDB, CSD and ICSD) to date. Almost 99.7% of them were obtained by approximating atoms as spheres within the independent atom model (IAM) introduced over a century ago. In this study, X-ray datasets for single crystals of hydrated α-oxalic acid were refined using several alternative electron density models that abandon the crude spherical approximation: the multipole model (MM), the transferable aspherical atom model (TAAM) and the Hirshfeld atom refinement (HAR) model as a function of the resolution of X-ray data. The aspherical models (MM, TAAM, HAR) give far more accurate and precise single-crystal X-ray results than IAM, sometimes identical to results obtained from neutron diffraction and at low resolution. Hence, aspherical approaches open new routes for improving existing structural information collected over the last century. |
BibTeX:
@article{FabiolaSanjuan-Szklarz2020,
author = {Fabiola Sanjuan-Szklarz, W. and Woińska, Magdalena and Domagala, Slawomir and Dominiak, Paulina M. and Grabowsky, Simon and Jayatilaka, Dylan and Gutmann, Matthias and Woźniak, Krzysztof},
title = {On the accuracy and precision of X-ray and neutron diffraction results as a function of resolution and the electron density model},
journal = {IUCrJ},
year = {2020},
volume = {7},
number = {5},
pages = {920--933},
url = {https://scripts.iucr.org/cgi-bin/paper?S2052252520010441},
doi = {10.1107/S2052252520010441}
}
|
| Fidrysiak M and Spałek J (2020), "Robust spin and charge excitations throughout the high-Tc cuprate phase diagram from incipient Mottness", Phys. Rev. B., Jul, 2020. Vol. 102(1), pp. 014505. |
| Abstract: The generic phase diagram of lightly hole doped high-Tc cuprates hosts an antiferromagnetic insulating phase with well-defined spin-wave excitations. Contrary to the weak-coupling prediction, these modes persist up to the overdoped metallic regime as intense and dispersive paramagnons. Here we report on our study of the low-energy magnetic and charge excitations within the extended Hubbard model at strong coupling, using a modified 1/N expansion method with a variational state serving as the saddle point solution. Despite clear separation of magnetic and Hubbard-U energy scales, we find that incipient Mottness affects qualitatively dispersions and widths of magnetic modes throughout the entire phase diagram. The obtained magnetic and charge dynamical structure factors agree semiquantitatively with recent resonant x-ray and neutron scattering data for La2-xSrxCuO4 and (Bi,Pb)2(Sr,La)2CuO6+δ at all available doping levels. The weak-coupling random-phase approximation fails already for underdoped samples, pointing to the nontrivial intertwining of distinct energy scales in cuprate superconductors. The existence of a discrete charge mode which splits off the electron-hole continuum is also predicted. |
BibTeX:
@article{Fidrysiak2020,
author = {Fidrysiak, M. and Spałek, J.},
title = {Robust spin and charge excitations throughout the high- Tc cuprate phase diagram from incipient Mottness},
journal = {Phys. Rev. B},
year = {2020},
volume = {102},
number = {1},
pages = {014505},
url = {https://link.aps.org/doi/10.1103/PhysRevB.102.014505},
doi = {10.1103/PhysRevB.102.014505}
}
|
| Guzman G, Rajendran V, Bao Z, Fang M-H, Pang W-K, Mahlik S, Leśniewski T, Grinberg M, Molokeev M, Leniec G, Chang H and Liu R-S (2020), "Multi-Site Cation Control of Ultra-Broadband Near-Infrared Phosphors for Application in Light-Emitting Diodes", Inorg. Chem.. Vol. 59(20), pp. 15101-15110. |
| Abstract: Near-infrared (NIR) phosphors are fascinating materials that have numerous applications in diverse fields. In this study, a series of La3Ga5GeO14:Cr3+ phosphors, which was incorporated with Sn4+, Ba2+, and Sc3+, was successfully synthesized using solid-state reaction to explore every cationic site comprehensively. The crystal structures were well resolved by combining synchrotron X-ray diffraction and neutron powder diffraction through joint Rietveld refinements. The trapping of free electrons induced by charge unbalances and lattice vacancies changes the magnetic properties, which was well explained by a Dyson curve in electron paramagnetic resonance. Temperature and pressure-dependent photoluminescence spectra reveal various luminescent properties between strong and weak fields in different dopant centers. The phosphor-converted NIR light-emitting diode (pc-NIR LED) package demonstrates a superior broadband emission that covers the near-infrared (NIR) region of 650-1050 nm. This study can provide researchers with new insight into the control mechanism of multiple-cation-site phosphors and reveal a potential phosphor candidate for practical NIR LED application. |
BibTeX:
@article{Guzman2020,
author = {Guzman, G.N.A.D. and Rajendran, V. and Bao, Z. and Fang, M.-H. and Pang, W.-K. and Mahlik, S. and Lesniewski, T. and Grinberg, M. and Molokeev, M.S. and Leniec, G. and Chang, H. and Liu, R.-S.},
title = {Multi-Site Cation Control of Ultra-Broadband Near-Infrared Phosphors for Application in Light-Emitting Diodes},
journal = {Inorg. Chem.},
year = {2020},
volume = {59},
number = {20},
pages = {15101--15110},
doi = {10.1021/acs.inorgchem.0c02055}
}
|
| Herbrych J, Alvarez G, Moreo A and Dagotto E (2020), "Block orbital-selective Mott insulators: A spin excitation analysis", Phys. Rev. B., Sep, 2020. Vol. 102(11), pp. 115134. |
| Abstract: We present a comprehensive study of the spin excitations- A s measured by the dynamical spin structure factor S(q,ω)-of the so-called block-magnetic state of low-dimensional orbital-selective Mott insulators. We realize this state via both a multi-orbital Hubbard model and a generalized Kondo-Heisenberg Hamiltonian. Due to various competing energy scales present in the models, the system develops periodic ferromagnetic islands of various shapes and sizes, which are antiferromagnetically coupled. The 2×2 particular case was already found experimentally in the ladder material BaFe2Se3 that becomes superconducting under pressure. Here we discuss the electronic density as well as Hubbard and Hund coupling dependence of S(q,ω) using density matrix renormalization group method. Several interesting features were identified: (1) An acoustic (dispersive spin-wave) mode develops. (2) The spin-wave bandwidth establishes a new energy scale that is strongly dependent on the size of the magnetic island and becomes abnormally small for large clusters. (3) Optical (dispersionless spin excitation) modes are present for all block states studied here. In addition, a variety of phenomenological spin Hamiltonians have been investigated but none matches entirely our results that were obtained primarily at intermediate Hubbard U strengths. Our comprehensive analysis provides theoretical guidance and motivation to crystal growers to search for appropriate candidate materials to realize the block states, and to neutron scattering experimentalists to confirm the exotic dynamical magnetic properties unveiled here, with a rich mixture of acoustic and optical features. |
BibTeX:
@article{Herbrych2020,
author = {Herbrych, J. and Alvarez, G. and Moreo, A. and Dagotto, E.},
title = {Block orbital-selective Mott insulators: A spin excitation analysis},
journal = {Phys. Rev. B},
year = {2020},
volume = {102},
number = {11},
pages = {115134},
url = {https://link.aps.org/doi/10.1103/PhysRevB.102.115134},
doi = {10.1103/PhysRevB.102.115134}
}
|
| Herbrych J, Heverhagen J, Alvarez G, Daghofer M, Moreo A and Dagotto E (2020), "Block–spiral magnetism: An exotic type of frustrated order", Proc. Natl. Acad. Sci., Jul, 2020. Vol. 117(28), pp. 16226-16233. |
| Abstract: Magnetic frustration in spin or electronic models emerges from the failure of the system to fulfill simultaneously conflicting local requirements. The latter typically arise from the lattice geometry or are induced by special spin–spin interactions in the system at various distances. Here we show that the competing energy scales of the seemingly nonfrustrated orbital-selective Mott phase of the low-dimensional multiorbital Hubbard model can originate a “block–chiral magnetism,” i.e., a state with rigidly rotating spin–magnetic islands. Furthermore, we show how such an exotic spin state influences the electronic properties of the system, revealing parity-breaking quasiparticles. |
BibTeX:
@article{Herbrych2020a,
author = {Herbrych, J. and Heverhagen, J. and Alvarez, G. and Daghofer, M. and Moreo, A. and Dagotto, E.},
title = {Block–spiral magnetism: An exotic type of frustrated order},
journal = {Proc. Natl. Acad. Sci.},
year = {2020},
volume = {117},
number = {28},
pages = {16226--16233},
url = {https://pnas.org/doi/full/10.1073/pnas.2001141117},
doi = {10.1073/pnas.2001141117}
}
|
| Jamroz J, Malys M, Krok F, Maier J, Kyriacou A, Ahmed S, Abrahams I and Wrobel W (2020), "The influence of defect structure changes at phase transition on electrical properties in the Bi0.75Pr0.25O1.5 oxide ion conductor", Solid State Ionics., May, 2020. Vol. 348, pp. 115284. |
| Abstract: The structural properties of Bi0.75Pr0.25O1.5 have been investigated by powder X-ray and neutron diffraction as a function of temperature up to around 800 °C. A layered rhombohedral structure is confirmed throughout the temperature range studied, with an order-disorder type phase transition (β2 ↔ β1) at ca. 730 °C. This transition is accompanied by partial migration of the oxide ions from the fluorite-like blocks of the layered structure to interstitial sites in the van der Waals gap between blocks. A reversible step change in total conductivity, associated with the phase transition, is preceded by non-linear behaviour observed in the Arrhenius plot of total conductivity at lower temperatures. A theoretical model based on a modification of the “cube-root” model successfully describes the conductivity data through the phase transition, showing the transition to involve a jump in inter-planar conductivity correlated with the appearance of interstitial oxide ions in the van der Waals gap. While the “cube root” model has been successfully used to explain phase transitions in classic 3-dimensional ionic conductors, the present study represents the first example of application of this model to a lower dimensional system. |
BibTeX:
@article{Jamroz2020,
author = {Jamroz, J. and Malys, M. and Krok, F. and Maier, J. and Kyriacou, A. and Ahmed, S.J. and Abrahams, I. and Wrobel, W.},
title = {The influence of defect structure changes at phase transition on electrical properties in the Bi0.75Pr0.25O1.5 oxide ion conductor},
journal = {Solid State Ionics},
year = {2020},
volume = {348},
pages = {115284},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167273819311439},
doi = {10.1016/j.ssi.2020.115284}
}
|
| Jha K, Gruza B, Kumar P, Chodkiewicz M and Dominiak P (2020), "TAAM: A reliable and user friendly tool for hydrogen-atom location using routine X-ray diffraction data", Acta Crystallogr. Sect. B Struct. Sci. Cryst. Eng. Mater.. Vol. 76, pp. 296-306. |
| Abstract: Hydrogen is present in almost all of the molecules in living things. It is very reactive and forms bonds with most of the elements, terminating their valences and enhancing their chemistry. X-ray diffraction is the most common method for structure determination. It depends on scattering of X-rays from electron density, which means the single electron of hydrogen is difficult to detect. Generally, neutron diffraction data are used to determine the accurate position of hydrogen atoms. However, the requirement for good quality single crystals, costly maintenance and the limited number of neutron diffraction facilities means that these kind of results are rarely available. Here it is shown that the use of Transferable Aspherical Atom Model (TAAM) instead of Independent Atom Model (IAM) in routine structure refinement with X-ray data is another possible solution which largely improves the precision and accuracy of X - H bond lengths and makes them comparable to averaged neutron bond lengths. TAAM, built from a pseudoatom databank, was used to determine the X - H bond lengths on 75 data sets for organic molecule crystals. TAAM parametrizations available in the modified University of Buffalo Databank (UBDB) of pseudoatoms applied through the DiSCaMB software library were used. The averaged bond lengths determined by TAAM refinements with X-ray diffraction data of atomic resolution (d min ≤ 0.83 Å) showed very good agreement with neutron data, mostly within one single sample standard deviation, much like Hirshfeld atom refinement (HAR). Atomic displacements for both hydrogen and non-hydrogen atoms obtained from the refinements systematically differed from IAM results. Overall TAAM gave better fits to experimental data of standard resolution compared to IAM. The research was accompanied with development of software aimed at providing user-friendly tools to use aspherical atom models in refinement of organic molecules at speeds comparable to routine refinements based on spherical atom model. |
BibTeX:
@article{Jha2020,
author = {Jha, K.K. and Gruza, B. and Kumar, P. and Chodkiewicz, M.L. and Dominiak, P.M.},
title = {TAAM: A reliable and user friendly tool for hydrogen-atom location using routine X-ray diffraction data},
journal = {Acta Crystallogr. Sect. B Struct. Sci. Cryst. Eng. Mater.},
year = {2020},
volume = {76},
pages = {296--306},
doi = {10.1107/S2052520620002917}
}
|
| Jóźwiak K, Jezierska A, Panek JJ, Goremychkin EA, Tolstoy PM, Shenderovich IG and Filarowski A (2020), "Inter-vs. Intramolecular Hydrogen Bond Patterns and Proton Dynamics in Nitrophthalic Acid Associates", Molecules., Oct, 2020. Vol. 25(20), pp. 4720. |
| Abstract: Noncovalent interactions are among the main tools of molecular engineering. Rational molecular design requires knowledge about a result of interplay between given structural moieties within a given phase state. We herein report a study of intra- and intermolecular interactions of 3-nitrophthalic and 4-nitrophthalic acids in the gas, liquid, and solid phases. A combination of the Infrared, Raman, Nuclear Magnetic Resonance, and Incoherent Inelastic Neutron Scattering spectroscopies and the Car–Parrinello Molecular Dynamics and Density Functional Theory calculations was used. This integrated approach made it possible to assess the balance of repulsive and attractive intramolecular interactions between adjacent carboxyl groups as well as to study the dependence of this balance on steric confinement and the effect of this balance on intermolecular interactions of the carboxyl groups. |
BibTeX:
@article{Jozwiak2020,
author = {Jóźwiak, Kinga and Jezierska, Aneta and Panek, Jarosław J. and Goremychkin, Eugene A. and Tolstoy, Peter M. and Shenderovich, Ilya G. and Filarowski, Aleksander},
title = {Inter- vs. Intramolecular Hydrogen Bond Patterns and Proton Dynamics in Nitrophthalic Acid Associates},
journal = {Molecules},
year = {2020},
volume = {25},
number = {20},
pages = {4720},
url = {https://www.mdpi.com/1420-3049/25/20/4720},
doi = {10.3390/molecules25204720}
}
|
| Keller T, Fabrykiewicz P, Przeniosło R, Sosnowska I and Keimer B (2020), "Neutron Larmor diffraction on powder samples Neutron Larmor diffraction on powder samples", J. Appl. Crystallogr.. Vol. 53, pp. 88-98. |
| Abstract: A hitherto unrecognized resolution effect in neutron Larmor diffraction (LD) is reported, resulting from small-angle neutron scattering (SANS) in the sample. Small distortions of the neutron trajectories by SANS give rise to a blurring of the Bragg angles of the order of a few hundredths of a degree, leading to a degradation of the momentum resolution. This effect is negligible for single crystals but may be significant for polycrystalline or powder samples. A procedure is presented to correct the LD data for the parasitic SANS. The latter is accurately determined by the SESANS technique (spin-echo small-angle neutron scattering), which is readily available on Larmor diffractometers. The analysis technique is demonstrated on LD and SESANS data from α-Fe2O3 powder samples. The resulting d-spacing range agrees with experimental data from high-resolution synchrotron radiation powder diffraction on the same sample. |
BibTeX:
@article{Keller2020,
author = {Keller, T. and Fabrykiewicz, P. and Przeniosło, R. and Sosnowska, I. and Keimer, B.},
title = {Neutron Larmor diffraction on powder samples Neutron Larmor diffraction on powder samples},
journal = {J. Appl. Crystallogr.},
year = {2020},
volume = {53},
pages = {88--98},
doi = {10.1107/S160057671901611X}
}
|
| Khomchenko VA, Silibin MV, Bushinsky MV, Latushka SI, Wiśniewski P, Łukowiak A, Franz A and Karpinsky DV (2020), "Increased Low‐Temperature Magnetization and Spin‐Reorientational Transition in the Polar Phase of (Ca, Mn)‐Doped Bismuth Ferrites", Phys. status solidi., Aug, 2020. Vol. 257(8), pp. 2000121. |
| Abstract: Solid-state synthesis and an investigation of the crystal/magnetic structure and magnetic properties of the Bi1−xCaxFe0.6Mn0.4O3+δ [x = 0.1, 0.15; δ = 0.02(2)] multiferroics have been conducted to explore an approach to designing ferroelectric materials with the enhanced magnetization attributed to the ferromagnetic superexchange involving the Mn 3d states. It is shown that the (Ca, Mn)-doped samples maintain the polar R3c structure characteristic of the pure bismuth ferrite. For both these compounds, an antiferromagnetic (AFM) G-type ordering of the Fe/Mn magnetic moments along the hexagonal c-axis is revealed at room temperature. The reorientation of the magnetic moments from the c- to a-axis occurs as temperature decreases. Being consistent with the competing character of the superexchange between Mn3+, Mn4+, and Fe3+ ions, the coexistence of AFM long-range-ordered and superparamagnetic phases underlying the appearance of a significant magnetization in the low-temperature range is observed. |
BibTeX:
@article{Khomchenko2020,
author = {Khomchenko, Vladimir A. and Silibin, Maxim V. and Bushinsky, Maxim V. and Latushka, Siarhei I. and Wiśniewski, Piotr and Łukowiak, Anna and Franz, Alexandra and Karpinsky, Dmitry V.},
title = {Increased Low‐Temperature Magnetization and Spin‐Reorientational Transition in the Polar Phase of (Ca, Mn)‐Doped Bismuth Ferrites},
journal = {Phys. status solidi},
year = {2020},
volume = {257},
number = {8},
pages = {2000121},
url = {https://onlinelibrary.wiley.com/doi/10.1002/pssb.202000121},
doi = {10.1002/pssb.202000121}
}
|
| Kierzek K and Gryglewicz G (2020), "Activated Carbons and Their Evaluation in Electric Double Layer Capacitors", Molecules., Sep, 2020. Vol. 25(18), pp. 4255. |
| Abstract: This review presents a summary of the manufacturing of activated carbons (ACs) as electrode materials for electric double layer capacitors. Commonly used techniques of open and closed porosity determination (gas adsorption, immersion calorimetry, X-ray and neutrons scattering) were briefly described. AC production methods (laboratory and industrial) were detailed presented with the stress on advantages and drawbacks of each ones in the field of electrode materials of supercapacitor. We discussed all general parameters of the activation process and their influence on the production efficiency and the porous structure of ACs. We showed that porosity development of ACs is not the only factor influencing capacity properties. The role of pore size distribution, raw material origin, final carbon structure ordering, particles morphology and purity must be also taken into account. The impact of surface chemistry of AC was considered not only in the context of pseudocapacity but also other important factors, such as inter-particle conductivity, maximal operating voltage window and long-term stability. |
BibTeX:
@article{Kierzek2020,
author = {Kierzek, Krzysztof and Gryglewicz, Grażyna},
title = {Activated Carbons and Their Evaluation in Electric Double Layer Capacitors},
journal = {Molecules},
year = {2020},
volume = {25},
number = {18},
pages = {4255},
url = {https://www.mdpi.com/1420-3049/25/18/4255},
doi = {10.3390/molecules25184255}
}
|
| Kot P, Baczmański A, Gadalińska E, Wroński S, Wroński M, Wróbel M, Bokuchava G, Scheffzük C and Wierzbanowski K (2020), "Evolution of phase stresses in Al/SiCp composite during thermal cycling and compression test studied using diffraction and self-consistent models", J. Mater. Sci. Technol.. Vol. 36, pp. 176-189. |
| Abstract: In this work, the evolutions of stresses in both phases of the Al/SiCp composite subjected to thermal cycling during in situ compression test were measured using Time of Flight neutron diffraction. It was confirmed that inter-phase stresses in the studied composite can be caused by differences in the coefficient of thermal expansion for the reinforcement and matrix, leading to a different variation of phase volumes during sample heating or cooling. The results of the diffraction experiment during thermal cycling were well predicted by the Thermo-Mechanical Self-Consistent model. The experimental study of elastic-plastic deformation was carried out in situ on a unique diffractometer EPSILON-MDS (JINR in Dubna, Russia) with nine detector banks measuring interplanar spacings simultaneously in 9 orientations of scattering vector. For the first time, the performed analysis of experimental data allowed to study the evolution of full stress tensor in both phases of the composite and to consider the decomposition of this tensor into deviatoric and hydrostatic components. It was found that the novel Developed Thermo-Mechanical Self-Consistent model correctly predicted stress evolution during compressive loading, taking into account the relaxation of thermal origin hydrostatic stresses. The comparison of this model with experimental data at the macroscopic level and the level of phases showed that strengthening of the Al/SiCp composite is caused by stress transfer from the plastically deformed Al2124 matrix to the elastic SiCp reinforcement, while thermal stresses relaxation does not significantly affect the overall composite properties. |
BibTeX:
@article{Kot2020,
author = {Kot, Przemysław and Baczmański, Andrzej and Gadalińska, Elżbieta and Wroński, Sebastian and Wroński, Marcin and Wróbel, Mirosław and Bokuchava, Gizo and Scheffzük, Christian and Wierzbanowski, Krzysztof},
title = {Evolution of phase stresses in Al/SiCp composite during thermal cycling and compression test studied using diffraction and self-consistent models},
journal = {J. Mater. Sci. Technol.},
year = {2020},
volume = {36},
pages = {176--189},
doi = {10.1016/j.jmst.2019.03.046}
}
|
| Kulka A, Marino C, Walczak K, Borca C, Bolli C, Novák P and Villevieille C (2020), "Influence of Na/Mn arrangements and P2/P′2 phase ratio on the electrochemical performance of Na: XMnO2 cathodes for sodium-ion batteries", J. Mater. Chem. A. Vol. 8(12), pp. 6022-6033. |
| Abstract: Among the candidate cathode materials for sodium-ion batteries (SIBs), NaxMnO2 (NMO) layered oxides are especially attractive in terms of working potential (ca. 3.0 V vs. Na+/Na) and high initial specific charge. In this work we discuss the influence of the sodium/manganese arrangements in P2 and P′2-Type phases and P2/P′2 phase ratio on the electrochemical performance of NMO electrodes. The detailed structural characterization of the materials was achieved by X-ray diffraction (XRD), neutron powder diffraction (NPD), inductively coupled plasma (ICP), and scanning electron microscopy (SEM/EDS). By combining the results from X-ray absorption spectroscopy (XAS), operando XRD, and online electrochemical mass spectrometry (OEMS) techniques we found that it is possible to change the reaction mechanisms from the P2 + P′2-Type → OP4-Type phase (observed for biphasic P2/P′2 NaxMnO2) to an intergrowth mechanism (single P2 NaxMnO2) by tuning the pristine composition. Additionally, we further discuss the influence of the reaction mechanism on the electrochemical performance. Based on the standard cycling protocol and rate capability tests we found that appropriate synergy of both P2 and P′2 is essential for obtaining NaxMnO2 electrodes with high specific charge offering long-Term cycling. |
BibTeX:
@article{Kulka2020,
author = {Kulka, Andrzej and Marino, Cyril and Walczak, Katarzyna and Borca, Camelia and Bolli, Christoph and Novák, Petr and Villevieille, Claire},
title = {Influence of Na/Mn arrangements and P2/P′2 phase ratio on the electrochemical performance of Na: XMnO2 cathodes for sodium-ion batteries},
journal = {J. Mater. Chem. A},
year = {2020},
volume = {8},
number = {12},
pages = {6022--6033},
doi = {10.1039/c9ta12176e}
}
|
| Kuzovnikov MA, Antonov VE, Ivanov AS, Hansen T, Savvin S, Kulakov VI, Tkacz M, Kolesnikov AI and Gurev VM (2020), "Neutron scattering study of tantalum dihydride", Phys. Rev. B., Jul, 2020. Vol. 102(2), pp. 024113. |
| Abstract: A single-phase sample of TaH2.2(1) with a hexagonal close-packed metal lattice (hcp; space group P63/mmc) was synthesized under a hydrogen pressure of 9 GPa and a temperature of 100 °C; quenched to the liquid nitrogen temperature; recovered to ambient pressure and studied by neutron diffraction (ND) and inelastic neutron scattering (INS). The ND study showed that hydrogen atoms occupied one half of the tetrahedral (T) and all octahedral (O) interstitial sites in the hcp lattice of Ta atoms. The arrangement of the H atoms over the T sites was proven to be ordered, which lowered the symmetry of the full crystal structure of the dihydride to P63mc. Due to the resulting asymmetry in the local environment of the O sites, the H atoms were considerably displaced from the centers of these sites along the z axis, away from the H atoms occupying the neighboring T sites. The INS study demonstrated that the potential wells for H atoms at both the T and O sites are highly anharmonic and anisotropic. The potential wells at the O sites are softer along the z axis than in the x, y plane, while the T sites show opposite anisotropy. |
BibTeX:
@article{Kuzovnikov2020,
author = {Kuzovnikov, Mikhail A. and Antonov, Vladimir E. and Ivanov, Alexandre S. and Hansen, Thomas and Savvin, Stanislav and Kulakov, Valery I. and Tkacz, Marek and Kolesnikov, Alexander I. and Gurev, Vladislav M.},
title = {Neutron scattering study of tantalum dihydride},
journal = {Phys. Rev. B},
year = {2020},
volume = {102},
number = {2},
pages = {024113},
url = {https://link.aps.org/doi/10.1103/PhysRevB.102.024113},
doi = {10.1103/PhysRevB.102.024113}
}
|
| Lakshminarayana G, Kumar A, Lira A, Dahshan A, Hegazy H, Kityk I, Lee D-E, Yoon J and Park T (2020), "Comparative study of gamma-ray shielding features and some properties of different heavy metal oxide-based tellurite-rich glass systems", Radiat. Phys. Chem., May, 2020. Vol. 170, pp. 108633. |
| Abstract: Tellurite-rich glasses containing Sm3+, Dy3+, and Er3+ ions with nominal chemical composition of 69 TeO2‒10 Bi2O3‒10 BaO‒10 ZnO‒1.0 Sm2O3/1.0 Dy2O3/1.0 Er2O3 (mol%) were fabricated. The gamma radiation attenuation features of the synthesized glasses were compared with two other tellurite glass systems with the chemical composition of 68 TeO2‒(22-x) Bi2O3‒10 ZnO‒ (x) PbO (x = 10, 12, 14, 16 and 18 mol%), and 75 TeO2‒20 B2O3‒5 MxOy (mol%) (MxOy = WO3, Nb2O5, PbO, Nd2O3, Y2O3). The mass attenuation coefficients (μ/ρ) (MAC) were computed from 0.015 MeV to 15 MeV photon energies using the XCOM program. Using the obtained μ/ρ values, effective atomic number (Zeff), electron density (Ne), half-value layer (HVL) and mean free path (MFP) were determined at different photon energies. The results clearly reveal that the MAC depends upon the heavy metals present in the studied glasses, and such addition increases the shielding capabilities of the samples against the gamma radiation. The Zeff and Ne confirmed the shielding effects with a variation in heavy metals content. The HVL and MFP values indicate the potential application in radiation insulation with less probability of interactions with gamma photons in the investigated tellurite glasses. It is found that the HVL or MFP values of the A ‒ C glasses lies in between the HVL or MFP values of the S1 – S5 and the T1 ‒ T5 glasses, respectively. Thus, the synthesized glasses are better shielding materials than the T1 – T5 glasses and possess slightly less gamma-ray shielding capacity than that of S1–S5 glasses. |
BibTeX:
@article{Lakshminarayana2020,
author = {Lakshminarayana, G. and Kumar, Ashok and Lira, A. and Dahshan, A. and Hegazy, H.H. and Kityk, I.V. and Lee, Dong-Eun and Yoon, Jonghun and Park, Taejoon},
title = {Comparative study of gamma-ray shielding features and some properties of different heavy metal oxide-based tellurite-rich glass systems},
journal = {Radiat. Phys. Chem.},
year = {2020},
volume = {170},
pages = {108633},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0969806X19306541},
doi = {10.1016/j.radphyschem.2019.108633}
}
|
| Malaspina L, Hoser A, Edwards A, Woińska M, Turner M, Price J, Sugimoto K, Nishibori E, Bürgi H-B, Jayatilaka D, Jayatilaka D and Grabowsky S (2020), "Hydrogen atoms in bridging positions from quantum crystallographic refinements: Influence of hydrogen atom displacement parameters on geometry and electron density", CrystEngComm. Vol. 22(28), pp. 4778-4789. |
| Abstract: Resonance-assisted hydrogen bonds (RAHBs) are exploited in chemical synthesis or serve as models for biologically relevant proton-transfer reactions [K. T. Mahmudov and A. J. L. Pombeiro, Chem.-Eur. J., 2016, 22, 16356-16398]. Their properties depend on the position of the hydrogen atom between donor and acceptor atoms. In the intramolecular RAHB of hydrogen maleate salts, this position is strongly influenced by the counter cation and varies from highly asymmetric to perfectly symmetric. This compound class is therefore ideally suited to investigate the factors determining geometry and electron density of intramolecular RAHBs. Here, it is shown that Hirshfeld atom refinements (HARs) of X-ray diffraction data of different hydrogen maleate salts can accurately and precisely match the hydrogen atom positions obtained from neutron diffraction and are independent of the model used for the hydrogen atom displacement parameters. Thus, the simplest, i.e. isotropic, HAR model can be used to locate hydrogen atoms also in bridging positions. In contrast, the determination of electron-density parameters with X-ray constrained wavefunction (XCW) fitting requires anisotropic, highly accurate hydrogen atom displacement parameters. This journal is |
BibTeX:
@article{Malaspina2020,
author = {Malaspina, L.A. and Hoser, A.A. and Edwards, A.J. and Woińska, M. and Turner, M.J. and Price, J.R. and Sugimoto, K. and Nishibori, E. and Bürgi, H.-B. and Jayatilaka, D. and Jayatilaka, D. and Grabowsky, S.},
title = {Hydrogen atoms in bridging positions from quantum crystallographic refinements: Influence of hydrogen atom displacement parameters on geometry and electron density},
journal = {CrystEngComm},
year = {2020},
volume = {22},
number = {28},
pages = {4778--4789},
doi = {10.1039/d0ce00378f}
}
|
| Małetka K, Ressouche E, Rundlof H, Tellgren R, Szczepaniak W and Zabłocka-Malicka M (2020), "Crystalline structures of Rb2UBr6 ionic conductor determined by neutron diffraction", Nukleonika., Mar, 2020. Vol. 65(1), pp. 3-11. |
| Abstract: The neutron powder diffraction technique has been used for structural studies of Rb 2 UBr 6 solid electrolyte as a function of temperature. The low-, room-, and high-temperature structures have been determined. At the temperature range of 4.2–80 K, the compound crystallizes in a monoclinic unit cell in the P21/c space group. At 80 K and 853 K, the compound crystallizes in a tetragonal unit cell in the P4/mnc space group. At 300 K, the lattice constants are a = b = 7.745(1) and c = 11.064(1) Å. At the temperature range of 853–960 K, a trigonal phase is observed in the Pʒ̄ml space group. |
BibTeX:
@article{Maetka2020,
author = {Małetka, Krzysztof and Ressouche, Eric and Rundlof, Hakan and Tellgren, Rolland and Szczepaniak, Włodzimierz and Zabłocka-Malicka, Monika},
title = {Crystalline structures of Rb 2 UBr 6 ionic conductor determined by neutron diffraction},
journal = {Nukleonika},
year = {2020},
volume = {65},
number = {1},
pages = {3--11},
url = {https://www.sciendo.com/article/10.2478/nuka-2020-0001},
doi = {10.2478/nuka-2020-0001}
}
|
| Mielewczyk-Gryń A, Wachowski S, Witkowska A, Dzierzgowski K, Skubida W, Świerczek K, Regoutz A, Payne D, Hull S, Zhang H, Abrahams I and Gazda M (2020), "Antimony substituted lanthanum orthoniobate proton conductor – Structure and electronic properties", J. Am. Ceram. Soc.. Vol. 103(11), pp. 6575-6585. |
| Abstract: X-ray and neutron diffraction have been utilized to analyze the crystalline and electronic structure of lanthanum orthoniobate substituted by antimony. Using X-ray absorption spectroscopy and photoelectron spectroscopy, changes in the electronic structure of the material upon substitution have been analyzed. The structural transition temperature between fergusonite and scheelite phases for 30 mol% antimony substitution was found to be 15°C. Based on the neutron data, the oxygen nonstoichiometry was found to be relatively low. Moreover no influence on the position of the valence band maximum was observed. The influence of the protonation on the electronic structure of constituent oxides has been studied. Absorption data show that the incorporation of protonic defects into the lanthanum orthoniobate structure leads to changes in lanthanum electronic structure and a decrease in the density of unoccupied electronic states. |
BibTeX:
@article{Mielewczyk-Gryn2020,
author = {Mielewczyk-Gryń, A. and Wachowski, S. and Witkowska, A. and Dzierzgowski, K. and Skubida, W. and Świerczek, K. and Regoutz, A. and Payne, D.J. and Hull, S. and Zhang, H. and Abrahams, I. and Gazda, M.},
title = {Antimony substituted lanthanum orthoniobate proton conductor – Structure and electronic properties},
journal = {J. Am. Ceram. Soc.},
year = {2020},
volume = {103},
number = {11},
pages = {6575--6585},
doi = {10.1111/jace.17352}
}
|
| Mihalik M, Roupcová P, Tarasenko R, Rams M, Hoser A and Mihalik M (2020), "Magnetism in NdMn0.1Fe0.9O3 compound", J. Magn. Magn. Mater., May, 2020. Vol. 502, pp. 166539. |
| Abstract: The low temperature crystal and magnetic structures of NdMn0.1Fe0.9O3 were determined on the basis of X-ray and neutron powder diffraction experiments as well as from specific heat and magnetization measurements. The compound crystallizes in the orthorhombic crystal structure, space group Pnma, in the entire temperature interval 20 mK < T < 300 K. The lattice parameters exhibit standard thermal expansion effects for T > 20 K and at lower temperatures the anomalies due to magnetostriction effect were observed. The iron sublattice orders magnetically into 3 different magnetic structures, namely into Γ5 = (Ax, Fy, Gz) for 130 K < T < TN (Néel temperature); Γ1 = (Gx, Cy, Az) for 15 K < T < 130 K and Γ3 = (Cx, Gy, Fz) for 20 mK < T < 15 K. The Nd ions order at temperatures below 1.6–1.75 K into the same Γ3 phase as the iron sublattice at these temperatures. The obtained magnetic structures fit perfectly in between the magnetic phases of closely related NdFeO3 and NdMn0.5Fe0.5O3 compounds. Our study, together with all previously published data, completes the entire magnetic phase diagram of NdMn1−xFexO3 (0 ≤ x ≤ 1) solid solution substitutional system. |
BibTeX:
@article{Mihalik2020,
author = {Mihalik, Matúš and Roupcová, Pavla and Tarasenko, Róbert and Rams, Michał and Hoser, Andreas and Mihalik, Marián},
title = {Magnetism in NdMn0.1Fe0.9O3 compound},
journal = {J. Magn. Magn. Mater.},
year = {2020},
volume = {502},
pages = {166539},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0304885319338909},
doi = {10.1016/j.jmmm.2020.166539}
}
|
| Nabiyev A, Olejniczak A, Pawlukojć A, Balasoiu M, Bunoiu M, Maharramov A, Nuriyev M, Ismayilova R, Azhibekov A, Kabyshev A, Turchenko V and Kuklin A (2020), "Nano-ZrO2 filled high-density polyethylene composites: Structure, thermal properties, and the influence γ-irradiation", Polym. Degrad. Stab.. Vol. 171, pp. 109042. |
| Abstract: High-density polyethylene (HDPE) composites with different amounts of ZrO2 nanoparticles (1–20 vol%) were prepared by high-pressure thermal pressing. The effect of γ-irradiation on their structural and thermal properties was investigated using small-angle neutron scattering (SANS), X-ray diffraction (XRD), Raman spectroscopy, infrared spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). SANS analysis confirmed good dispersion of the nanoparticles in HDPE matrix. Upon exposure to γ-radiation only small changes in the lattice parameters and the crystalinity degree occurred for both HDPE and the nanocomposities. More significant changes for irradiated HDPE were observed in DSC-derived parameters, including the decrease in the melting point, and increase in crystalinity degree. This trend was even more pronounced for the nanocomposities. A possible explanation assuming resonant enchantment of polymer chain scission in the presence of ZrO2 nanoparticles is discussed. The extent of radiation-induced oxidation was essentially the same for pure HDPE and the nanocomposities, suggesting that the process is diffusion controlled. The thermal stability of the irradiated composites was somehow higher than that pure HDPE. |
BibTeX:
@article{Nabiyev2020,
author = {Nabiyev, A.A. and Olejniczak, A. and Pawlukojc, A. and Balasoiu, M. and Bunoiu, M. and Maharramov, A.M. and Nuriyev, M.A. and Ismayilova, R.S. and Azhibekov, A.K. and Kabyshev, A.M. and Turchenko, V.A. and Kuklin, A.I.},
title = {Nano-ZrO2 filled high-density polyethylene composites: Structure, thermal properties, and the influence γ-irradiation},
journal = {Polym. Degrad. Stab.},
year = {2020},
volume = {171},
pages = {109042},
doi = {10.1016/j.polymdegradstab.2019.109042}
}
|
| Need RF, Bac S-K, Liu X, Lee S, Kirby BJ, Dobrowolska M, Kossut J and Furdyna JK (2020), "Magnetic properties and electronic origin of the interface between dilute magnetic semiconductors with orthogonal magnetic anisotropy", Phys. Rev. Mater., May, 2020. Vol. 4(5), pp. 054410. |
| Abstract: Controlling changes in magnetic anisotropy across epitaxial film interfaces is an important prerequisite for many spintronic devices. For the canonical dilute magnetic semiconductor GaMnAs, magnetic anisotropy is highly tunable through strain and doping, making it a fascinating model system for exploration of anisotropy control in a carrier-mediated ferromagnet. Here, we have used transmission electron microscopy and polarized neutron reflectometry to characterize the interface between GaMnAs-based layers designed to have anisotropy vectors oriented at right angles from one another. For a bilayer of Ga1-xMnxAs1-yPy and Ga1-xMnxAs, we find that the entirety of the Ga1-xMnxAs layer exhibits in-plane magnetic anisotropy and that the majority of the Ga1-xMnxAs1-yPy exhibits perpendicular anisotropy. However, near the Ga1-xMnxAs interface, we observe a thin Mn-rich region of the nominally perpendicular Ga1-xMnxAs1-yPy that instead exhibits in-plane anisotropy. Using first-principles energy considerations, we explain this sublayer as a natural consequence of interfacial carrier migration. |
BibTeX:
@article{Need2020,
author = {Need, Ryan F. and Bac, Seul-Ki and Liu, Xinyu and Lee, Sanghoon and Kirby, Brian J. and Dobrowolska, Margaret and Kossut, Jacek and Furdyna, Jacek K.},
title = {Magnetic properties and electronic origin of the interface between dilute magnetic semiconductors with orthogonal magnetic anisotropy},
journal = {Phys. Rev. Mater.},
year = {2020},
volume = {4},
number = {5},
pages = {054410},
url = {https://link.aps.org/doi/10.1103/PhysRevMaterials.4.054410},
doi = {10.1103/PhysRevMaterials.4.054410}
}
|
| Pajerowski DM, Manson JL, Herbrych J, Bendix J, Podlesnyak AA, Cain JM and Meisel MW (2020), "Inelastic neutron scattering study of the anisotropic S=1 spin chain [Ni(HF2)(3-Clpyridine)4] BF4", Phys. Rev. B., Mar, 2020. Vol. 101(9), pp. 094431. |
| Abstract: [Ni(HF2)(3-Clpyridine)4]BF4 (NBCT) is a one-dimensional, S=1 spin chain material that shows no magnetic neutron Bragg peaks down to temperatures of 0.1 K. Previous work identified NBCT as being in the Haldane phase and near a quantum phase transition as a function of D/J to the large-D quantum paramagnet phase (QPM), where D is the axial single-ion anisotropy and J is the intrachain superexchange. Herein, inelastic neutron scattering results are presented on partially deuterated, B11-enriched NBCT polycrystalline samples in zero magnetic field and down to temperatures of 0.3 K. Comparison to density matrix renormalization group calculations yields D/J=1.51 and a significant rhombic single-ion anisotropy E (E/D≈0.03, E/J≈0.05). These D, J, and E values place NBCT in the large-D QPM phase but precipitously near a quantum phase transition to a long-range ordered phase. |
BibTeX:
@article{Pajerowski2020,
author = {Pajerowski, Daniel M. and Manson, Jamie L. and Herbrych, Jacek and Bendix, Jesper and Podlesnyak, Andrey A. and Cain, John M. and Meisel, Mark W.},
title = {Inelastic neutron scattering study of the anisotropic S=1 spin chain [Ni(HF2)(3-Clpyridine)4] BF4},
journal = {Phys. Rev. B},
year = {2020},
volume = {101},
number = {9},
pages = {094431},
url = {https://link.aps.org/doi/10.1103/PhysRevB.101.094431},
doi = {10.1103/PhysRevB.101.094431}
}
|
| Pajzderska A, Jenczyk J, Embs J and Wąsicki J (2020), "Exploring molecular reorientations in amorphous and recrystallized felodipine at the microscopic level", RSC Adv.. Vol. 10(61), pp. 37346-37357. |
| Abstract: Molecular reorientations were studied in amorphous, partially and fully recrystallized felodipine (calcium channel blocker, a drug from the family of 1′,4-dihydropyridine) using a set of experimental methods: high-resolution solid-state nuclear magnetic resonance (NMR), relaxometry NMR and quasielastic neutron scattering (QENS). The results were compared with molecular dynamics in crystalline felodipine previously investigated [A. Pajzderska, K. Drużbicki, M. A. Gonzalez, J. Jenczyk, J. Mielcarek, J. Wasicki, Diversity of Methyl Group Dynamics in Felodipine: a DFT Supported NMR and Neutron Scattering Study,CrystEngComm, 2018,20, 7371-7385]. The kinetics of the recrystallization was also studied. The most stable sample was the sample stored in a closed ampoule (at room temperature, in 0% RH) and its complete recrystallization lasted 105 days. In the fully recrystallized sample, the same molecular reorientation identified in the crystalline form was detected, so reorientations of all methyl groups and the ethyl ester fragment. In the partially recrystallized sample, static disorder caused by the two positions of both side chains was revealed. In the amorphous sample the reorientation of all methyl groups was analyzed and the distribution of correlation times and energy barriers connected with the loss of long-range ordering and disorder of side chains were analyzed. Additionally, inhibition of reorientation in the ethyl ester fragment was observed. |
BibTeX:
@article{Pajzderska2020,
author = {Pajzderska, A. and Jenczyk, J. and Embs, J.P. and Wasicki, J.},
title = {Exploring molecular reorientations in amorphous and recrystallized felodipine at the microscopic level},
journal = {RSC Adv.},
year = {2020},
volume = {10},
number = {61},
pages = {37346--37357},
doi = {10.1039/d0ra07266d}
}
|
| Pandey B, Lin LF, Soni R, Kaushal N, Herbrych J, Alvarez G and Dagotto E (2020), "Prediction of exotic magnetic states in the alkali-metal quasi-one-dimensional iron selenide compound Na2FeSe2", Phys. Rev. B., Jul, 2020. Vol. 102(3), pp. 035149. |
| Abstract: The magnetic and electronic phase diagram of a model for the quasi-one-dimensional alkali-metal iron selenide compound Na2FeSe2 is presented. The novelty of this material is that the valence of iron is Fe2+, contrary to most other iron-chain compounds with valence Fe3+. Using first-principles techniques, we developed a three-orbital tight-binding model that reproduces the ab initio band structure near the Fermi level. Including Hubbard and Hund couplings and studying the model via the density-matrix renormalization group and Lanczos methods, we constructed the ground-state phase diagram. A robust region where the block state ↑↑↓↓↑↑↓↓ is stabilized was unveiled. The analog state in iron ladders, employing 2×2 ferromagnetic blocks, is by now well established, but in chains a block magnetic order has not been observed yet in real materials. The phase diagram also contains a large region of canonical staggered spin order ↑↓↑↓↑↓↑ at very large Hubbard repulsion. At the block-to-staggered transition region, an exotic phase is stabilized with a mixture of both states: an inhomogeneous orbital-selective charge density wave with the exotic spin configuration ↑↑↓↑↓↓↑↓. Our predictions for Na2FeSe2 may guide crystal growers and neutron-scattering experimentalists towards the realization of block states in one-dimensional iron selenide chain materials. |
BibTeX:
@article{Pandey2020,
author = {Pandey, Bradraj and Lin, Ling Fang and Soni, Rahul and Kaushal, Nitin and Herbrych, Jacek and Alvarez, Gonzalo and Dagotto, Elbio},
title = {Prediction of exotic magnetic states in the alkali-metal quasi-one-dimensional iron selenide compound Na2FeSe2},
journal = {Phys. Rev. B},
year = {2020},
volume = {102},
number = {3},
pages = {035149},
url = {https://link.aps.org/doi/10.1103/PhysRevB.102.035149},
doi = {10.1103/PhysRevB.102.035149}
}
|
| Penc B, Baran S, Hoser A, Przewoźnik J and Szytuła A (2020), "Magnetic properties and magnetic structures of R2PdGe6 (R = Pr, Nd, Gd-Er) and R2PtGe6 (R = Tb, Ho, Er)", J. Magn. Magn. Mater., Nov, 2020. Vol. 514, pp. 167152. |
| Abstract: Polycrystalline samples of the intermetallic compounds R2PdGe6 (R = Pr, Nd, Gd-Er) and R2PtGe6 (R = Tb, Ho, Er) have been studied using X-ray diffraction as well as magnetometric and neutron diffraction measurements. All compounds have an orthorhombic crystal structure of the Yb2PdGe6-type (space group Cmca) and are antiferromagnetic with the Néel temperatures ranging from 4.9 K for Er2PtGe6 up to 48 K for Tb2PdGe6. The magnetic properties and specific heat data collected for Nd2PdGe6 show the presence of an additional phase transition below TN at T = 4 K. Based on the neutron diffraction data, the magnetic structures have been determined for R2PdGe6 (R = Pr, Nd, Tb, Dy, Ho) and R2PtGe6 (R = Tb and Er). Both the magnetic properties and neutron diffraction data indicate that the magnetic moment is localized on rare earth atoms. The magnetic unit cell is equal to the crystal one, however, individual compounds show different types of magnetic orderings. Magnetic moments in Pr2PdGe6 form a non-collinear antiferromagnetic structure at low temperatures with magnetic moments confined to the (0 0 1) plane. The low temperature magnetic structure in Nd2PdGe6 is a collinear antiferromagnetic one with moments parallel to the b-axis and coupled ferromagnetically within the (0 0 1) plane, while along the c-axis the moments follow the + − − + sequence. With increasing temperature, a transition to a modulated magnetic structure is observed in Nd2PdGe6 at T = 4 K. The magnetic moments in R2PdGe6 (R = Tb, Dy, Ho) and Tb2PtGe6 assume a non-collinear antiferromagnetic order within the (0 0 1) plane with the + − + − sequence of signs of the moments in the neighboring planes along the c-axis. The Er moments in Er2PtGe6 form a collinear magnetic structure with magnetic moments oriented along the a-axis and coupled ferromagnetically within the (0 0 1) plane. Along the c-axis the moments follow the + − + − sequence. The magnetic structures determined here are discussed on the basis of the competition between the RKKY-type interactions and influence of Crystalline Electric Field. |
BibTeX:
@article{Penc2020,
author = {Penc, Bogusław and Baran, Stanisław and Hoser, Andreas and Przewoźnik, Janusz and Szytuła, Andrzej},
title = {Magnetic properties and magnetic structures of R2PdGe6 (R = Pr, Nd, Gd-Er) and R2PtGe6 (R = Tb, Ho, Er)},
journal = {J. Magn. Magn. Mater.},
year = {2020},
volume = {514},
pages = {167152},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0304885320305795},
doi = {10.1016/j.jmmm.2020.167152}
}
|
| Piękoś P, Jezierska A, Panek J, Goremychkin E, Pozharskii A, Antonov A, Tolstoy P and Filarowski A (2020), "Symmetry/asymmetry of the NHN hydrogen bond in protonated 1,8-bis(Dimethylamino)naphthalene", Symmetry (Basel).. Vol. 12(11), pp. 1-26. |
| Abstract: Experimental and theoretical results are presented based on vibrational spectra and motional dynamics of 1,8-bis(dimethylamino)naphthalene (DMAN) and its protonated forms (DMANH+ and the DMANH+ HSO4− complex). The studies of these compounds have been performed in the gas phase and solid-state. Spectroscopic investigations were carried out by infrared spectroscopy (IR), Raman, and incoherent inelastic neutron scattering (IINS) experimental methods. Density functional theory (DFT) and Car–Parrinello molecular dynamics (CPMD) methods were applied to support our experimental findings. The fundamental investigations of hydrogen bridge vibrations were accomplished on the basis of isotopic substitutions (NH → ND). Special attention was paid to the bridged proton dynamics in the DMANH+ complex, which was found to be affected by interactions with the HSO4− anion. |
BibTeX:
@article{Piekos2020,
author = {Piękoś, P. and Jezierska, A. and Panek, J.J. and Goremychkin, E.A. and Pozharskii, A.F. and Antonov, A.S. and Tolstoy, P.M. and Filarowski, A.},
title = {Symmetry/asymmetry of the NHN hydrogen bond in protonated 1,8-bis(Dimethylamino)naphthalene},
journal = {Symmetry (Basel).},
year = {2020},
volume = {12},
number = {11},
pages = {1--26},
doi = {10.3390/sym12111924}
}
|
| Popov EP, Chernikov AN, Beskrovnyi AI, Waliszewski J and Mirzayev MN (2020), "Cryostat for cooling samples in the study of low-temperature structural and magnetic phase transitions by neutron diffraction", J. Phys. Conf. Ser., Apr, 2020. Vol. 1492(1), pp. 012054. |
| Abstract: A vertical cryostat was developed built around a Sumitomo RDK-101D cold head. The cryostat is intended for investigating the structure and phase transformations of different materials via neutron diffraction experiments on samples under high vacuum of up to 10 −5 mbar. A working temperature of the sample close to 2 K was reached. The drift diameter of the head is 54 mm, making it possible to cool samples with a height of 55 mm and 15 mm in diameter. Test measurements were conducted and illustrative spectra were recorded on the example of a sample of HoFeO 3 . The cryostat was designed and manufactured at the Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research. |
BibTeX:
@article{Popov2020,
author = {Popov, E P and Chernikov, A N and Beskrovnyi, A I and Waliszewski, J. and Mirzayev, M N},
title = {Cryostat for cooling samples in the study of low-temperature structural and magnetic phase transitions by neutron diffraction},
journal = {J. Phys. Conf. Ser.},
year = {2020},
volume = {1492},
number = {1},
pages = {012054},
url = {https://iopscience.iop.org/article/10.1088/1742-6596/1492/1/012054},
doi = {10.1088/1742-6596/1492/1/012054}
}
|
| Rećko K, Satuła D, Waliszewski J, Biernacka M, Orzechowska M, Kalska-Szostko B, Soloviov D, Miaskowski A, Beskrovnyy A, Basa A, Basa A and Szymański K (2020), "Magnetism of Surface-Modified and Gallium-Doped Magnetite Particles", J. Surf. Investig.. Vol. 14, pp. S85-S92. |
| Abstract: Abstract: New data on gallium ferrite particles are reported. The results of studies of Fe3O4/GaxFe3 – xO4 and GaxFe3 – xO4/Fe3O4 (x = 0.2, 0.4, 0.6 and 0.8) nanoparticles by X-ray and neutron diffraction, small angle neutron scattering, transmission electron microscopy, magnetization measurements, and Mössbauer spectroscopy. The cubic core–shell ferrites structures were confirmed as single phases with a cell parameter of ∼8.388 Å independent of gallium content. The lack of preferences in occupancies of gallium sites was confirmed. The magnetic structure at room temperature, the stability of a disaggregated dispersion of nanoparticles in the temperature range 20–50°C, the radii of the cores, and the thickness of the coating layers, as well as the specific absorption of electromagnetic radiation rates were characterized. |
BibTeX:
@article{Recko2020,
author = {Rećko, K. and Satuła, D. and Waliszewski, J. and Biernacka, M. and Orzechowska, M. and Kalska-Szostko, B. and Soloviov, D. and Miaskowski, A. and Beskrovnyy, A. and Basa, A. and Basa, A. and Szymański, K.},
title = {Magnetism of Surface-Modified and Gallium-Doped Magnetite Particles},
journal = {J. Surf. Investig.},
year = {2020},
volume = {14},
pages = {S85--S92},
doi = {10.1134/S102745102007040X}
}
|
| Reszczyńska J, Pylak M, Fornalski K, Mortazavi S and Dobrzyński L (2020), "Methodological problems in epidemiological data: The case of correlation between radon level and lung cancer", Int. J. Low Radiat.. Vol. 11(3-4), pp. 207-226. |
| Abstract: This paper focuses on the relationship between radon concentration and lung cancer morbidity from the methodological point of view. Geographically aggregated data on cancer risk factors, collected for 3142 US counties and county-equivalents are discussed. Apart from the Least-Squares and Bayesian linear regression analysis, for the first time the Maximum Entropy Method (MEM) is used to investigate this type of correlation, where major confounding factors under considerations are altitude and ultraviolet (type B) radiation. First two methods of analysis show statistically significant decrease in the group with the high smoking prevalence. This trend did not depend on the sex of the subjects or their prevalence of smoking. The use of MEM provides a much richer picture of a clear trend of decreasing morbidity of lung cancer with increasing radon concentration level. Last but not least, it is shown that the data binning has to be made carefully as otherwise the conclusions based on the data can be dubious. |
BibTeX:
@article{Reszczynska2020,
author = {Reszczyńska, J. and Pylak, M. and Fornalski, K.W. and Mortazavi, S.J. and Dobrzyński, L.},
title = {Methodological problems in epidemiological data: The case of correlation between radon level and lung cancer},
journal = {Int. J. Low Radiat.},
year = {2020},
volume = {11},
number = {3-4},
pages = {207--226},
doi = {10.1504/IJLR.2020.113541}
}
|
| Rok M, Moskwa M, Dopieralski P, Medycki W, Zamponi M and Bator G (2020), "The influence of structure on the methyl group dynamics of polymorphic complexes: 6,6′-dimethyl-2,2′-dipyridyl with halo derivatives of benzoquinone acids", CrystEngComm. Vol. 22(41), pp. 6811-6821. |
| Abstract: Recently, interest in organic ferroelectrics or antiferroelectrics representing a metal-free perovskite-type has increased significantly. This interest results from the properties of organic systems. First of all, they do not have toxic metals in their structure. Therefore they are environmentally friendly. Also, the method of preparation, simple syntheses, and low-temperature processability increase their attractiveness in terms of application. In this paper, the above properties are associated with the proton dynamics in organic donor-acceptor systems. We present the comparison of the physicochemical properties of four molecular complexes containing the proton acceptor molecule, 6,6′-dimethyl-2,2′-bipyridyl (66DMBP), and one of three organic acid molecules belonging to the benzoquinone group. As proton donor molecules the organic acids: chloranilic, bromanilic and iodanilic acids have been chosen. We present the results of experiments concerning the determination of crystal structures, 1H NMR, inelastic neutron scattering (INS) and UV/vis spectra. In the theoretical part, we attempt to explain the influence of the crystallization method (a type of solvent) on transoid or cisoid arrangement of 66DMBP. In the theoretical approach, we focus on two forms of the complex with chloranilic acid, α-66DMBPtextperiodcenteredCLA and β-66DMBPtextperiodcenteredCLA, which undergo solid-to-solid phase transitions, at 380 and 317 K, respectively. We have chosen these examples because the α analogue possesses ferroelectric properties in a wide range of temperatures. This journal is |
BibTeX:
@article{Rok2020,
author = {Rok, M. and Moskwa, M. and Dopieralski, P. and Medycki, W. and Zamponi, M. and Bator, G.},
title = {The influence of structure on the methyl group dynamics of polymorphic complexes: 6,6′-dimethyl-2,2′-dipyridyl with halo derivatives of benzoquinone acids},
journal = {CrystEngComm},
year = {2020},
volume = {22},
number = {41},
pages = {6811--6821},
doi = {10.1039/d0ce00973c}
}
|
| Rotnicki K, Sterczyńska A, Fojud Z, Jażdżewska M, Beskrovnyi A, Waliszewski J and Śliwińska-Bartkowiak M (2020), "Phase transitions, molecular dynamics and structural properties of 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquid", J. Mol. Liq., Sep, 2020. Vol. 313, pp. 113535. |
| Abstract: Recently, ionic liquids are very promising substances mentioned in electrochemistry as electrolytes in supercapacitors. Due to the fact the operation conditions for supercapacitors require low temperatures, an important issue is an investigation of melting behavior of ionic liquid applied as an electrolyte. In the presented work, we report the experimental studies of the melting behavior of 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM TFSI); for this purpose the methods of dielectric spectroscopy (DS) and differential scanning calorimetry (DSC) in wide temperature ranges were applied. To investigate the structural properties of the system the temperature-controlled WAXS and Neutron Diffraction methods were adopted. The measurements of the complex permittivity of the studied EMIM TFSI allowed us to determine the relaxation of the system in wide temperature range from 140 K to 300 K. The results obtained from DSC and DS indicate that the ionic liquid on the heating process undergoes two phase transitions: solid-solid transition at temperature 230 K and the melting transition at 257 K, wherein the melting process is not homogeneous. Based on the structural studies results, performed in the temperatures range 10 K – room temperature, it was shown that in the temperature range 10 K–230 K EMIM TFSI forms a crystal monoclinic structure where the rotation motions of molecular groups are observed. At the higher temperature up to the melting temperature the crystal structure is undefined and the rotational motions of molecular groups are changed. |
BibTeX:
@article{Rotnicki2020,
author = {Rotnicki, Konrad and Sterczyńska, Angelina and Fojud, Zbigniew and Jażdżewska, Monika and Beskrovnyi, Anatolii and Waliszewski, Janusz and Śliwińska-Bartkowiak, Małgorzata},
title = {Phase transitions, molecular dynamics and structural properties of 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquid},
journal = {J. Mol. Liq.},
year = {2020},
volume = {313},
pages = {113535},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167732220306486},
doi = {10.1016/j.molliq.2020.113535}
}
|
| Sheka E, Natkaniec I, Ipatova E, Golubev Y, Kabachkov E and Popova V (2020), "Heteroatom necklaces of sp2 amorphous carbons. XPS supported INS and DRIFT spectroscopy", Fullerenes Nanotub. Carbon Nanostructures. Vol. 28(12), pp. 1010-1029. |
| Abstract: In the case of sp2 amorphous carbons, formed by nanoscale graphene domains framed by heteroatom necklaces (basic structure units in total), inelastic neutron scattering and photoabsorption ensure studying vibrational spectra of the latter mainly. Examination of a set of samples of the highest carbonization rank representing natural substances (shungite carbon, anthraxolite, and anthracite), technical graphenes (laboratory reduced graphene oxides), and industrial products (carbon blacks) has shown, that while INS spectra revealed the hydrogen-enriched component of these necklaces only, the DRIFT spectra exhibited two components determined by both hydrogen and oxygen compositions. Taking together, INS and DRIFT spectra exhibit methine groups, typifying the hydrogen component of all natural amorphics as well as hydroxymethyls and methyls doing the same job for the studied technical graphenes, and hydroxyfurans - for carbon blacks. A comparable analysis of DRIFT and XPS spectra has allowed a reliable personification of the oxygen functional groups compositions. Based on the results obtained, a set of reliable molecular models of the amorphics' basic structural units has been proposed. |
BibTeX:
@article{Sheka2020,
author = {Sheka, E.F. and Natkaniec, I. and Ipatova, E.U. and Golubev, Y.A. and Kabachkov, E.N. and Popova, V.A.},
title = {Heteroatom necklaces of sp2 amorphous carbons. XPS supported INS and DRIFT spectroscopy},
journal = {Fullerenes Nanotub. Carbon Nanostructures},
year = {2020},
volume = {28},
number = {12},
pages = {1010--1029},
doi = {10.1080/1536383X.2020.1794849}
}
|
| Singh A, Rajput S, Balasubramanian P, Anas M, Damay F, Kumar CM, Eguchi G, Jain A, Yusuf SM, Maitra T and Malik VK (2020), "Successive spin reorientations and rare earth ordering in Nd0.5Dy0.5Fe O3: Experimental and ab initio investigations", Phys. Rev. B., Oct, 2020. Vol. 102(14), pp. 144432. |
| Abstract: In the present paper, the magnetic structure and spin reorientation of mixed rare-earth orthoferrite Nd0.5Dy0.5FeO3 have been investigated. At room temperature, our neutron-diffraction measurements reveal that the magnetic structure of Fe3+ spins in Nd0.5Dy0.5FeO3 belongs to Γ4 irreducible representation (Gx, Fz) as observed in both parent compounds (NdFeO3 and DyFeO3). The neutron-diffraction study also confirms the presence of a spin-reorientation transition where the magnetic structure of Fe3+ spins changes from Γ4 to Γ2(Fx, Gz) representation between 75 and 20 K while maintaining a G-type antiferromagnetic configuration. Such a gradual spin reorientation is unusual since the large single ion anisotropy of Dy3+ ions is expected to cause an abrupt Γ4→1(Gy) rotation of the Fe3+ spins. At 10 K, the Fe3+ magnetic structure is represented by Γ2 (Fx, Gz). Unexpectedly, the Γ4 structure of Fe3+ spins re-emerges below 10 K, which also coincides with the development of rare-earth (Nd3+/Dy3+) magnetic ordering having cyR configuration. Such re-emergence of a magnetic structure has been a rare phenomenon in orthoferrites. The absence of a second-order phase transition in rare-earth ordering, interpreted from heat capacity data, suggests the prominent role of Nd3+-Fe3+ and Nd3+-Dy3+ exchange interactions. These interactions suppress the independent rare-earth magnetic ordering observed in both parent compounds due to Nd3+/Dy3+-Nd3+/Dy3+ exchange interactions. Our density-functional-theory calculations including Coulomb correlation and spin-orbit interaction effects (DFT+U+SO) reveal that the C-type arrangement of rare-earth ions (Nd3+/Dy3+), with Γ2 (Fx, Gz) configuration for Fe3+ moments, is energetically very close to a phase with the same rare-earth magnetic ordering but Γ4 (Gx, Fz) configuration of Fe3+ spins. Further, the Nd3+-Fe3+ and Nd3+-Dy3+ exchange interactions are observed to play significant roles in the complex Fe3+ spin reorientation with the re-emergence of Γ4 at low temperature. Consistent with the experimental observations, our calculations established the mixed phase (Γ2 and Γ4) to be the magnetic ground state of Fe3+ moments. |
BibTeX:
@article{Singh2020,
author = {Singh, Ankita and Rajput, Sarita and Balasubramanian, Padmanabhan and Anas, M. and Damay, Francoise and Kumar, C. M.N. and Eguchi, Gaku and Jain, A. and Yusuf, S. M. and Maitra, T. and Malik, V. K.},
title = {Successive spin reorientations and rare earth ordering in Nd0.5Dy0.5Fe O3: Experimental and ab initio investigations},
journal = {Phys. Rev. B},
year = {2020},
volume = {102},
number = {14},
pages = {144432},
url = {https://link.aps.org/doi/10.1103/PhysRevB.102.144432},
doi = {10.1103/PhysRevB.102.144432}
}
|
| Sliwinska-Bartkowiak M, Jażdżewska M, Beskrovnyi A and Gubbins KE (2020), "Phase transitions of water confined in nanopores", In AIChE Annu. Meet. Conf. Proc.. Vol. 2020-Novem |
| Abstract: Phenomena that occur only at very high pressures in the bulk phase are often observed to occur in the confined phaseat normal pressures. Abundant experimental evidence suggests that adsorbates confined in nanoporous carbonsexhibit high pressures, such as high-pressure crystal structures, high-pressure chemical reactions, and thedeformation of pore walls due to the adsorbate. Also molecular simulation studies of the pressure tensor for simpleadsorbates in carbon nanopores of slit, cylindrical and spherical geometries show that for modest bulk phasepressures the pressure parallel to the pore walls is of the order of GPa, while the pressure normal to the wall is of theorder of hundreds of MPa [1,2]. We report X-ray, neutrons diffraction ( ND) and dielectric studies of ice confined in activated carbon fibres (ACFs). Thefibres are built of turbostratic nanoparticles separated by quasi two-dimensional voids, forming narrow slit-shapedpores. The structure of ice in cylindrical nanocarbons pores (CMK-3), which are the reverse carbon replica of silicaSBA-15 matrices, was also analyzed. The results show strong evidence for the presence of both hexagonal and cubicforms of ice confined in all of the systems studied. We were not able to obtain a good Rietveld refinement of ourdiffraction patterns with typical hexagonal and cubic forms of ice; but we observe that the formation of the ice structurein the pores, has been attributed to the restrictions on the size of the crystallite and the quasi-high pressure effect inpores. However, according to recently published work [3], the cubic form of ice is not exactly cubic, but containsstacking faults instead of an ordered arrangement of two dimensional layers. This form of ice is in fact a stacking-disordered material containing cubic sequences interlaced with hexagonal sequences. The structure of the confinedice observed in our experiments in nanocarbons pores corresponds to disordered stacking ice Isd,, which wasidentified as having the space group P3m1 [3,4]. We observe,that the stacking disorder can vary in complexitydepending on the nature of the pore walls and on the prevailing thermal conditions during the ice formation. Ananalysis of the kind of I formed in ACF and CMK-3 of different pore sizes will be presented. These crystal forms,which occur in bulk water only at temperatures below 180 K in the case of cubic ice, and at pressures of hundreds ofMPa are stabilized by the confinement. |
BibTeX:
@inproceedings{Sliwinska-Bartkowiak2020,
author = {Sliwinska-Bartkowiak, M. and Jazdzewska, M. and Beskrovnyi, A. and Gubbins, K. E.},
title = {Phase transitions of water confined in nanopores},
booktitle = {AIChE Annu. Meet. Conf. Proc.},
year = {2020},
volume = {2020-Novem}
}
|
| Szpunar I, Wachowski S, Miruszewski T, Dzierzgowski K, Górnicka K, Klimczuk T, Sørby M, Balaguer M, Serra J, Strandbakke R, Gazda M and Mielewczyk-Gryń A (2020), "Electric and magnetic properties of lanthanum barium cobaltite", J. Am. Ceram. Soc.. Vol. 103(3), pp. 1809-1818. |
| Abstract: The cubic Ba0.5La0.5CoO3-δ was synthesized using solid state reaction. The structural properties were determined by the simultaneous refinement of Synchrotron Powder X-ray Diffraction and Neutron Powder Diffraction data. Iodometric titration was used to examine the oxygen stoichiometry and average cobalt oxidation state. Low-temperature magnetic studies show soft ferromagnetic character of fully oxidized material, with θP = 198(3) K and µeff = 2.11(2) µB. Electric measurements show the thermally activated nature of conductivity at low temperatures, whereas, due to the variable oxidation and spin state of cobalt, a single charge transport mechanism cannot be distinguished. Around room temperature, a wide transition from thermally activated conductivity to semi-metallic behavior is observed. Under the inert atmosphere, the oxygen content lowers and the cation ordering takes place, leading to coexistence of two, ordered and disordered, phases. As a result of this change, thermally activated conductivity is observed also at high temperatures in inert atmosphere. |
BibTeX:
@article{Szpunar2020,
author = {Szpunar, I. and Wachowski, S. and Miruszewski, T. and Dzierzgowski, K. and Górnicka, K. and Klimczuk, T. and Sørby, M.H. and Balaguer, M. and Serra, J.M. and Strandbakke, R. and Gazda, M. and Mielewczyk-Gryń, A.},
title = {Electric and magnetic properties of lanthanum barium cobaltite},
journal = {J. Am. Ceram. Soc.},
year = {2020},
volume = {103},
number = {3},
pages = {1809--1818},
doi = {10.1111/jace.16865}
}
|
| Turchenko VA, Trukhanov A, Trukhanov S, Damay F, Porcher F, Balasoiu M, Lupu N, Chiriac H, Bozzo B, Fina I, Waliszewski J, Kostishyn VG, Rećko K and Polosan S (2020), "Magnetic and ferroelectric properties, crystal and magnetic structures of SrFe11.9In0.1O19", Phys. Scr., Feb, 2020. Vol. 95(4), pp. 044006. |
| Abstract: The structural investigations of SrFe11.9In0.1O19 compound synthesized by solid-state method have been carried by neutron diffraction method in a wide temperature range. The appearace of spontaneous polarization that coexists with ferrimagnetic ordering has been found out at room temperature in strontium hexaferrite partially substituted with In ions. In order to explaine the presence of ferroelectric properties in SrFe11.9In0.1O19 compound, its crystal structure has been refined within the framework of both centrosymmetric P63/mmc (No. 194) and non-centrosymmetric P63mc (No. 186) space groups. The analysis of refinement results allows to understand microscopic mechanism of appearance ferroelectric properties in strontium hexaferrites. |
BibTeX:
@article{Turchenko2020a,
author = {Turchenko, V A and Trukhanov, A. and Trukhanov, S. and Damay, F. and Porcher, F. and Balasoiu, M. and Lupu, N. and Chiriac, H. and Bozzo, B. and Fina, I. and Waliszewski, J and Kostishyn, V G and Recko, K. and Polosan, S.},
title = {Magnetic and ferroelectric properties, crystal and magnetic structures of SrFe11.9In0.1O19},
journal = {Phys. Scr.},
year = {2020},
volume = {95},
number = {4},
pages = {044006},
url = {https://iopscience.iop.org/article/10.1088/1402-4896/ab60fb},
doi = {10.1088/1402-4896/ab60fb}
}
|
| Turchenko V, Kostishyn V, Trukhanov S, Damay F, Porcher F, Balasoiu M, Lupu N, Bozzo B, Fina I, Trukhanov A, Waliszewski J, Recko K and Polosan S (2020), "Crystal and magnetic structures, magnetic and ferroelectric properties of strontium ferrite partially substituted with in ions", J. Alloys Compd., Apr, 2020. Vol. 821, pp. 153412. |
| Abstract: The influence of temperature factor to crystal structure as well as magnetic and electric properties of strontium hexaferrite partially substituted with diamagnetic indium ions has been investigated. Ferroelectric properties have been found out in SrFe11.9In0.1O19 compound that contradicts to conventional opinion, which describe its crystal structure within the framework of centrosymmetric space group P63/mmc (No. 194). For determination features of the crystal structure, which are responsible for ferroelectric properties of strontium hexaferrite, have been carried out neutron diffraction measurements with high resolution in temperature range from 1.5 to 740 K. The analysis of hexaferrite structure has been executed within the framework both centrosymmetric and non-centrosymmetric space group. Values of coefficients of magneto crystalline anisotropy at 5 and 300 K and influence of ambient temperature to linear size of magnetic regions have been determined from magnetic measurements. |
BibTeX:
@article{Turchenko2020,
author = {Turchenko, Vitalii and Kostishyn, V.G. and Trukhanov, Sergei and Damay, Francoise and Porcher, Florence and Balasoiu, Maria and Lupu, Nicoleta and Bozzo, Bernar and Fina, Ignasi and Trukhanov, Alex and Waliszewski, Janusz and Recko, Katarzyna and Polosan, Silviu},
title = {Crystal and magnetic structures, magnetic and ferroelectric properties of strontium ferrite partially substituted with in ions},
journal = {J. Alloys Compd.},
year = {2020},
volume = {821},
pages = {153412},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838819346584},
doi = {10.1016/j.jallcom.2019.153412}
}
|
| Wachowski SL, Szpunar I, Sørby MH, Mielewczyk-Gryń A, Balaguer M, Ghica C, Istrate MC, Gazda M, Gunnæs AE, Serra JM, Norby T and Strandbakke R (2020), "Structure and water uptake in BaLnCo2O6−δ (Ln =La, Pr, Nd, Sm, Gd, Tb and Dy)", Acta Mater., Oct, 2020. Vol. 199, pp. 297-310. |
| Abstract: The structure of BaLnCo2O6-δ (Ln =La, Pr, Nd, Sm, Gd, Tb and Dy) was studied by the means of synchrotron radiation powder X-ray diffraction, neutron powder diffraction and Transmission Electron Microscopy (TEM), while water uptake properties were analysed with the use of thermogravimetry (TG) and water adsorption isotherms. The structure refinement revealed that the dominant phase in all compositions was orthorhombic with an ordering of the A-site cations along the c-axis and ordering of oxygen vacancies along the b-axis, which was also directly evidenced by TEM. It was shown that both unit cell volume and average Co-oxidation state at room temperature decrease linearly with decreasing Ln radius. TG water uptake experiments in humidified N2–O2 gas mixture at 300 °C revealed that among all compositions, only BaLaCo2O6-δ and BaGdCo2O6-δ exhibit significant water uptake. Surface water adsorption studies showed that the α, a normalised parameter reflecting the surface hydrophilicity, mostly independently of Ln radius was close to 0.5, which means that the surface is neither hydrophobic nor hydrophilic. The results indicated that water uptake observed at 300 °C is a bulk process, which cannot be described by standard hydration/hydrogenation reaction and it is related to the layered structure of the perovskite lattice and characteristic to La or Gd being present in the lattice. |
BibTeX:
@article{Wachowski2020,
author = {Wachowski, Sebastian Lech and Szpunar, Iga and Sørby, Magnus Helgerud and Mielewczyk-Gryń, Aleksandra and Balaguer, María and Ghica, Corneliu and Istrate, Marian Cosmin and Gazda, Maria and Gunnæs, Anette E. and Serra, José M. and Norby, Truls and Strandbakke, Ragnar},
title = {Structure and water uptake in BaLnCo2O6−δ (Ln =La, Pr, Nd, Sm, Gd, Tb and Dy)},
journal = {Acta Mater.},
year = {2020},
volume = {199},
pages = {297--310},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1359645420306157},
doi = {10.1016/j.actamat.2020.08.018}
}
|
| Yu B, Tabis W, Bialo I, Yakhou F, Brookes NB, Anderson Z, Tang Y, Yu G and Greven M (2020), "Unusual Dynamic Charge Correlations in Simple-Tetragonal HgBa2CuO4+δ", Phys. Rev. X., Jun, 2020. Vol. 10(2), pp. 021059. |
| Abstract: The charge-density-wave (CDW) instability in the underdoped, pseudogap part of the cuprate phase diagram has been a major recent research focus, yet measurements of dynamic, energy-resolved charge correlations are still in their infancy. Such information is crucial in order to help discern the connection between CDW and pseudogap phenomena, and to understand the extent to which charge correlations in general shape the phase diagram. We report a resonant inelastic x-ray scattering study of the underdoped cuprate superconductor HgBa2CuO4+δ (Tc=70 K). At 250 K, above the previously established temperature TCDW≈200 K that signifies the onset of quasistatic short-range CDW order, we observe significant dynamic correlations that are broadly peaked at about 40 meV and centered at the two-dimensional wave vector qCDW. This energy scale is comparable to both the superconducting gap and the low-energy pseudogap. At 70 K, we observe a quasistatic CDW peak at qCDW, but the dynamic correlations around 40 meV remain virtually unchanged, and we identify a new feature: dynamic correlations well above the optic phonon range that are broadly peaked in the 150-200 meV range. A similar energy scale was previously identified in other experiments as a high-energy pseudogap. The observation of three distinct features in the charge response is highly unusual for a CDW system and suggests that charge order in the cuprates is complex. We demonstrate that other single-layer cuprates exhibit approximately the same relative strength of high- to low-temperature energy-integrated charge signal, which points to the universal existence of significant dynamic correlations. Intriguingly, the two energy scales identified here are also comparable to those of the superconducting glue function extracted from other spectroscopic techniques, consistent with a dual charge and magnetic nature of the pairing glue. We further determine the paramagnon dispersion along [1, 0], across qCDW, and find it to be consistent with magnetic excitations measured by inelastic neutron scattering. Unlike for some other cuprates, our result points to the absence of a discernible coupling between charge and magnetic excitations. |
BibTeX:
@article{Yu2020,
author = {Yu, B. and Tabis, W. and Bialo, I. and Yakhou, F. and Brookes, N. B. and Anderson, Z. and Tang, Y. and Yu, G. and Greven, M.},
title = {Unusual Dynamic Charge Correlations in Simple-Tetragonal HgBa2CuO4+δ},
journal = {Phys. Rev. X},
year = {2020},
volume = {10},
number = {2},
pages = {021059},
url = {https://link.aps.org/doi/10.1103/PhysRevX.10.021059},
doi = {10.1103/PhysRevX.10.021059}
}
|
| Łuczyńska K, Drużbicki K, Runka T, Pałka N and Węsicki J (2020), "Vibrational Response of Felodipine in the THz Domain: Optical and Neutron Spectroscopy Versus Plane-Wave DFT Modeling", J. Infrared, Millimeter, Terahertz Waves. Vol. 41(11), pp. 1301-1336. |
| Abstract: We present a joint experimental and computational terahertz (THz) spectroscopy study of the most stable polymorph (form I) of an antihypertensive pharmaceutical solid, felodipine (FLD). The vibrational response has been analyzed at room temperature by combining optical (THz-TDS, FT-IR, THz-Raman) and neutron (INS) terahertz spectroscopy. With the challenging example of a large and flexible molecular solid, we illustrate the complementarity of the experimental techniques. We show how the results can be understood by employing ab initio modeling and discuss current progress in the field. To this end, we employ plane wave formulation of density functional theory (plane wave DFT) along with harmonic lattice dynamics calculations (HLD) and ab initio molecular dynamics (AIMD) simulations. Based on a comprehensive theoretical analysis, we discover an inconsistency in the commonly accepted structural model, which can be linked to a distinct librational dynamics of the side ester chains. As a result, only a moderate agreement with the experimental spectra can be achieved. We, therefore, propose an alternative structural model, effectively accounting for the influence of the large-amplitude librations and allowing for a comprehensive analysis of the vibrational resonances up to 4.5 THz. In that way, we illustrate the applicability of the computationally supported THz spectroscopy to detect subtle structural issues in molecular solids. While the provided structural model can be treated as a guess, the problem calls for further revision by means of high-resolution crystallography. The problem also draws a need of extending the THz experiments toward low-temperature conditions and single-crystal samples. On the other hand, the studied system emerges as a challenge for the DFT modeling, being extremely sensitive to the level of the theory used and the resulting description of the intermolecular forces. FLD form I can be, hence, considered as a testbed for the use of more sophisticated theoretical approaches, particularly relying on an advanced treatment of the van der Walls forces and going beyond zero-temperature conditions and harmonic approximation. |
BibTeX:
@article{uczynska2020,
author = {Łuczyńska, K. and Drużbicki, K. and Runka, T. and Pałka, N. and Węsicki, J.},
title = {Vibrational Response of Felodipine in the THz Domain: Optical and Neutron Spectroscopy Versus Plane-Wave DFT Modeling},
journal = {J. Infrared, Millimeter, Terahertz Waves},
year = {2020},
volume = {41},
number = {11},
pages = {1301--1336},
doi = {10.1007/s10762-019-00634-9}
}
|
| Łudzik K, Woloszczuk S, Zając W, Jażdżewska M, Rogachev A, Kuklin A, Zawisza A and Jóźwiak M (2020), "Can the isothermal calorimetric curve shapes suggest the structural changes in micellar aggregates?", Int. J. Mol. Sci.. Vol. 21(16), pp. 1-24. |
| Abstract: Inspired by the unusual shapes of the titration curve observed for many surfactants and mixed colloidal systems, we decided to extend the analysis to isothermal titration calorimetric curves (ITC) by paying special attention to potential structural changes in micellar aggregates. In this paper, we used isothermal titration calorimetry in conjunction with Scanning Transmission Electron Microscopy (STEM), Small-Angle Neutron Scattering (SANS) and X-ray Scattering (SAXS) methods support by Monte Carlo and semiempirical quantum chemistry simulations to confirm if the isothermal calorimetric curve shape can reflect micelle transition phenomena. For that purpose, we analysed, from the thermodynamic point of view, a group of cationic gemini surfactants, alkanediyl-α,ω-bis(dimethylalkylammonium) bromides. We proposed the shape of aggregates created by surfactant molecules in aqueous solutions and changes thereof within a wide temperature range. The results provide evidence for the reorganization processes and the relationship (dependence) between the morphology of the created aggregates and the conditions such as temperature, surfactant concentration and spacer chain length which affect the processes. |
BibTeX:
@article{udzik2020,
author = {Łudzik, K. and Woloszczuk, S. and Zajac, W. and Jazdzewska, M. and Rogachev, A. and Kuklin, A.I. and Zawisza, A. and Jóźwiak, M.},
title = {Can the isothermal calorimetric curve shapes suggest the structural changes in micellar aggregates?},
journal = {Int. J. Mol. Sci.},
year = {2020},
volume = {21},
number = {16},
pages = {1--24},
doi = {10.3390/ijms21165828}
}
|
| Abib K, Azzeddine H, Alili B, Lityńska-Dobrzyńska L, Helbert A, Baudin T, Jegou P, Mathon M, Zieba P and Bradai D (2019), "Cr cluster characterization in Cu-Cr-Zr alloy after ECAP processing and aging using SANS and HAADF-STEM", Kov. Mater.. Vol. 57(2), pp. 121-129. |
| Abstract: The precipitation of nano-sized Cr clusters was investigated in a commercial Cu-1Cr-0.1Zr (wt.%) alloy processed by equal-channel angular pressing and subsequent aging at 550 ◦ C for 4 h using Small-Angle Neutron Scattering (SANS) measurements and High-Angle Annular Dark-Field-Scanning Transmission Electron Microscopy (HAADF-STEM). The size and volume fraction of the nano-sized Cr clusters were estimated using both techniques. The parameter values assessed by SANS (d ∼ 3.2 nm, Fv ∼ 1.1 %) agreed reasonably with those by HAADF-STEM (d ∼ 2.5 nm, Fv ∼ 2.3 %). In addition to the nano-sized Cr clusters, HAADF-STEM indicated the presence of rare cuboid and spheroid sub-micronic Cr particles measuring approximately 380–620 nm in mean size. Both techniques did not evidence the presence of intermetallic CuxZry phases within the aging conditions. |
BibTeX:
@article{Abib2019,
author = {Abib, K. and Azzeddine, H. and Alili, B. and Lityńska-Dobrzyńska, L. and Helbert, A.L. and Baudin, T. and Jegou, P. and Mathon, M.H. and Zieba, P. and Bradai, D.},
title = {Cr cluster characterization in Cu-Cr-Zr alloy after ECAP processing and aging using SANS and HAADF-STEM},
journal = {Kov. Mater.},
year = {2019},
volume = {57},
number = {2},
pages = {121--129},
doi = {10.4149/km_2019_1_121}
}
|
| Babilas R, Bajorek A and Temleitner L (2019), "Structural study of amorphous and nanocrystalline Mg-based metallic glass examined by neutron diffraction, X-ray photoelectron spectroscopy, Reverse Monte Carlo calculations and high-resolution electron microscopy", J. Non. Cryst. Solids., Feb, 2019. Vol. 505, pp. 421-430. |
| Abstract: The microstructure of amorphous and nanocrystalline Mg65Cu20Y10Zn5 alloy in as-quenched and post-annealed state was examined using neutron diffraction (ND), Reverse Monte Carlo modeling (RMC) and high-resolution transmission electron microscopy (HRTEM). The surface characteristic of Mg-based glass was investigated by X-ray photoelectron spectroscopy (XPS) method. The corrosion activity of alloy in glassy and nanocrystalline state was determined by electrochemical polarization measurements conducted in 3.5% NaCl solution. It was found that the structure of the melt-spun glass is homogeneous, but some medium-range order (MRO) regions as small as 1–2 nm were observed. The RMC analysis of ND data was used for local atomic structure and coordination numbers of the Mg65Cu20Y10Zn5 alloy in as-quenched state. The three-dimensional model representing a simulation box with atomic arrangements was also proposed. An average coordination number for Mg-Mg and Mg-Cu atoms is 8.1 and 2.5, adequately. The formation of nanocrystalline structure after annealing was confirmed by X-ray diffraction (XRD) and HRTEM observations. The TEM and HRTEM techniques allowed to observe regions containing very small particles in the amorphous matrix with size of 4–10 nm. The selected area electron diffraction (SAED) patterns allowed to identified hexagonal Mg and orthorhombic Mg2Cu phases. XPS results indicated the co-existence of MgO and Mg(OH)2 on the surface film formed on glassy ribbon in as-quenched state. The electrochemical polarization measurements revealed that the glassy ribbon exhibited lower corrosion current density than nanocrystalline sample. |
BibTeX:
@article{Babilas2019,
author = {Babilas, Rafał and Bajorek, Anna and Temleitner, Laszlo},
title = {Structural study of amorphous and nanocrystalline Mg-based metallic glass examined by neutron diffraction, X-ray photoelectron spectroscopy, Reverse Monte Carlo calculations and high-resolution electron microscopy},
journal = {J. Non. Cryst. Solids},
year = {2019},
volume = {505},
pages = {421--430},
url = {https://linkinghub.elsevier.com/retrieve/pii/S002230931830680X},
doi = {10.1016/j.jnoncrysol.2018.11.025}
}
|
| Baran S, Hoser A, Rams M, Ostrovsky S, Neumann T, Näther C and Tomkowicz Z (2019), "Neutron diffraction study of quasi-1D Ising ferromagnet [Co(NCS)2(pyridine)2]", J. Phys. Chem. Solids., Jul, 2019. Vol. 130, pp. 290-297. |
| Abstract: The quasi-one-dimensional [Co(NCS) 2 (pyridine) 2 ] n coordination polymer built of ferromagnetic chains of Co(II) ions linked by (NCS) 2 anions is known as an Ising ferromagnet that magnetically orders at T C = 3.9 K. We performed a neutron diffraction study and show that the magnetic structure is collinear ferromagnetic, static, and without any glassy component. The magnitude of the ordered magnetic moment of Co(II) is 3.65(15) μ B , which points to a relatively large contribution of the orbital moment. The direction of the moment is close to the direction of the Co–N(pyridine) bond, which confirms literature ab initio calculations. We show that dipolar interactions are mainly responsible for the magnetic interchain coupling. |
BibTeX:
@article{Baran2019,
author = {Baran, Stanisław and Hoser, Andreas and Rams, Michał and Ostrovsky, Serghei and Neumann, Tristan and Näther, Christian and Tomkowicz, Zbigniew},
title = {Neutron diffraction study of quasi-1D Ising ferromagnet [Co(NCS)2(pyridine)2]},
journal = {J. Phys. Chem. Solids},
year = {2019},
volume = {130},
pages = {290--297},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0022369718310205},
doi = {10.1016/j.jpcs.2018.11.001}
}
|
| Belova I, Ahmed T, Sarder U, Yi Wang W, Kozubski R, Liu Z-K, Holland-Moritz D, Meyer A and Murch G (2019), "Computer simulation of thermodynamic factors in Ni-Al and Cu-Ag liquid alloys", Comput. Mater. Sci.. Vol. 166, pp. 124-135. |
| Abstract: In this paper, thermodynamic factors of two liquid alloys, Ni-Al and Cu-Ag, are studied by means of molecular dynamics simulation (with the most reliable embedded-atom method potentials)over both wide composition and temperature ranges. For the first time, a comparison is possible between Ni-Al (with a strong ordering tendency)and Cu-Ag (with a strong phase separation tendency). The calculations were performed based on the evaluation of pair correlation functions and mean square thermal fluctuations in composition (the thermodynamic limit of one of the Bhatia-Thornton partial structure factors, SCC). A novel but straightforward computational approach is developed and successfully applied to these calculations. In order to ensure reliability of the employed model description of Ni-Al liquid alloys, the calculated partial and total structure factors are verified by data from neutron scattering experimental measurements (performed as part of this work as well as also being available in the literature). Good agreement is observed for the structure factor SCC for all values of q including the thermodynamic limit q→0. On the other hand, for the total and Faber-Ziman partial structure factors, good agreement is observed only for q values outside the limit q→0. In addition, a similarity between the shapes of the thermodynamic factor composition dependence and the shape of the liquidus lines in both Ni-Al and Cu-Ag liquid alloys is noted. We highlight the significance of the presented computational and experimental study for developing and testing various models and frameworks. |
BibTeX:
@article{Belova2019,
author = {Belova, I.V. and Ahmed, T. and Sarder, U. and Yi Wang, W. and Kozubski, R. and Liu, Z.-K. and Holland-Moritz, D. and Meyer, A. and Murch, G.E.},
title = {Computer simulation of thermodynamic factors in Ni-Al and Cu-Ag liquid alloys},
journal = {Comput. Mater. Sci.},
year = {2019},
volume = {166},
pages = {124--135},
doi = {10.1016/j.commatsci.2019.04.048}
}
|
| Borkowski M, Buchachenko AA, Ciuryło R, Julienne PS, Yamada H, Kikuchi Y, Takasu Y and Takahashi Y (2019), "Weakly bound molecules as sensors of new gravitylike forces", Sci. Rep., Oct, 2019. Vol. 9(1), pp. 14807. |
| Abstract: Several extensions to the Standard Model of particle physics, including light dark matter candidates and unification theories predict deviations from Newton's law of gravitation. For macroscopic distances, the inverse-square law of gravitation is well confirmed by astrophysical observations and laboratory experiments. At micrometer and shorter length scales, however, even the state-of-the-art constraints on deviations from gravitational interaction, whether provided by neutron scattering or precise measurements of forces between macroscopic bodies, are currently many orders of magnitude larger than gravity itself. Here we show that precision spectroscopy of weakly bound molecules can be used to constrain non-Newtonian interactions between atoms. A proof-of-principle demonstration using recent data from photoassociation spectroscopy of weakly bound Yb 2 molecules yields constraints on these new interactions that are already close to state-of-the-art neutron scattering experiments. At the same time, with the development of the recently proposed optical molecular clocks, the neutron scattering constraints could be surpassed by at least two orders of magnitude. |
BibTeX:
@article{Borkowski2019,
author = {Borkowski, Mateusz and Buchachenko, Alexei A. and Ciuryło, Roman and Julienne, Paul S. and Yamada, Hirotaka and Kikuchi, Yuu and Takasu, Yosuke and Takahashi, Yoshiro},
title = {Weakly bound molecules as sensors of new gravitylike forces},
journal = {Sci. Rep.},
year = {2019},
volume = {9},
number = {1},
pages = {14807},
url = {https://www.nature.com/articles/s41598-019-51346-y},
doi = {10.1038/s41598-019-51346-y}
}
|
| Borowska-Centkowska A, Liu X, Kryński M, Leszczyńska M, Wróbel W, Malys M, Hull S, Norberg ST, Krok F and Abrahams I (2019), "Defect structure in δ-Bi5PbY2O11.5", RSC Adv.. Vol. 9(17), pp. 9640-9653. |
| Abstract: A detailed study of the defect structure in a di-substituted δ-Bi2O3 type phase, δ-Bi5PbY2O11.5, is presented. Using a combination of conventional Rietveld analysis of neutron diffraction data, reverse Monte Carlo (RMC) analysis of total neutron scattering data and ab initio molecular dynamics (MD) simulations, both average and local structures have been characterized. δ-Bi5PbY2O11.5 represents a model system for the highly conducting δ-Bi2O3 type phases, in which there is a higher nominal vacancy concentration than in the unsubstituted parent compound. Uniquely, the methodology developed in this study has afforded the opportunity to study both oxide-ion vacancy ordering as well as specific cation-cation interactions. Oxide-ion vacancies in this system have been found to show a preference for association with Pb2+ cations, with some evidence for clustering of these cations. The system shows a non-random distribution of vacancy pair alignments, with a preference for 〈100〉 ordering, the extent of which shows thermal variation. MD simulations indicate a predominance of oxide-ion jumps in the 〈100〉 direction. |
BibTeX:
@article{Borowska-Centkowska2019,
author = {Borowska-Centkowska, Anna and Liu, Xi and Krynski, Marcin and Leszczynska, Marzena and Wrobel, Wojciech and Malys, Marcin and Hull, Stephen and Norberg, Stefan T. and Krok, Franciszek and Abrahams, Isaac},
title = {Defect structure in δ-Bi5PbY2O11.5},
journal = {RSC Adv.},
year = {2019},
volume = {9},
number = {17},
pages = {9640--9653},
url = {http://xlink.rsc.org/?DOI=C9RA01233H},
doi = {10.1039/c9ra01233h}
}
|
| Burian A, Dore JC and Jurkiewicz K (2019), "Structural studies of carbons by neutron and x-ray scattering", Reports Prog. Phys., Jan, 2019. Vol. 82(1), pp. 016501. |
| Abstract: Carbon can have many different forms and the characterisation of structural features on a length scale of 1 Å to 10 μm is important in defining its physical and chemical properties for the various forms. The use of either electro-magnetic (x-ray) or particle (neutron) beams plays an important role in determining these characteristics. In this paper, we review the various techniques that are used to determine the structural features by experimental means and how the data are processed to give the required information in a suitable form for detailed analysis by computer simulation. Diffraction methods are used for studies of the atomic arrangement and small-angle scattering techniques are used for studies of microporosity in the sample materials. The experimental data obtained from a wide range of different carbon materials are considered and how these results can be used as a basis for modelling the structures in a quantitative manner is also considered. This information underpins their use as active components in a wide range of functional materials. |
BibTeX:
@article{Burian2019,
author = {Burian, Andrzej and Dore, John C and Jurkiewicz, Karolina},
title = {Structural studies of carbons by neutron and x-ray scattering},
journal = {Reports Prog. Phys.},
year = {2019},
volume = {82},
number = {1},
pages = {016501},
url = {https://iopscience.iop.org/article/10.1088/1361-6633/aae882},
doi = {10.1088/1361-6633/aae882}
}
|
| Chapagain K, Brown DE, Kolesnik S, Lapidus S, Haberl B, Molaison J, Lin C, Kenney-Benson C, Park C, Pietosa J, Markiewicz E, Andrzejewski B, Lynn JW, Rosenkranz S, Dabrowski B and Chmaissem O (2019), "Tunable multiferroic order parameters in Sr1-xBaxMn1-yTiyO3", Phys. Rev. Mater., Aug, 2019. Vol. 3(8), pp. 084401. |
| Abstract: Responding to the rapidly increasing demand for efficient energy usage and increased speed and functionality of electronic and spintronic devices, multiferroic oxides have recently emerged as key materials capable of tackling this multifaceted challenge. In this paper, we describe the development of single-site manganese-based multiferroic perovskite materials with modest amounts of nonmagnetic Ti substituted at the magnetic Mn site in Sr1-xBaxMn1-yTiyO3 (SBMTO). Significantly enhanced properties were achieved with ferroelectric-type structural transition temperatures boosted to ∼430K. Ferroelectric distortions with large spontaneous polarization values of ∼30μC/cm2, derived from a point charge model, are similar in magnitude to those of the prototypical nonmagnetic BaTiO3. Temperature dependence of the system's properties was investigated by synchrotron X-ray powder diffraction and neutron powder diffraction at ambient and high pressures. Various relationships were determined between the structural and magnetic properties, Ba and Ti contents, and TN and TC. Most importantly, our results demonstrate the large coupling between the magnetic and ferroelectric order parameters and the wide tunability of this coupling by slight variations of the material's stoichiometry. |
BibTeX:
@article{Chapagain2019,
author = {Chapagain, Kamal and Brown, Dennis E. and Kolesnik, Stanislaw and Lapidus, Saul and Haberl, Bianca and Molaison, Jamie and Lin, Chuanlong and Kenney-Benson, Curtis and Park, Changyong and Pietosa, Jaroslaw and Markiewicz, Ewa and Andrzejewski, Bartlomiej and Lynn, Jeffrey W. and Rosenkranz, Stephan and Dabrowski, Bogdan and Chmaissem, Omar},
title = {Tunable multiferroic order parameters in Sr1-xBaxMn1-yTiyO3},
journal = {Phys. Rev. Mater.},
year = {2019},
volume = {3},
number = {8},
pages = {084401},
url = {https://link.aps.org/doi/10.1103/PhysRevMaterials.3.084401},
doi = {10.1103/PhysRevMaterials.3.084401}
}
|
| Chatterji T, Rols S and Wdowik UD (2019), "Dynamics of the phase-change material GeTe across the structural phase transition", Front. Phys., Apr, 2019. Vol. 14(2), pp. 23601. |
| Abstract: Results of inelastic neutron scattering experiments and ab initio molecular dynamics simulations for GeTe–the parent compound of phase-change materials are reported. The inelastic neutron spectra of GeTe powder samples have been determined in the temperature range extending from 300 to 700 K. The phonon peaks undergo thermal shifts resulting from anharmonic effects being weaker for acoustic than optic modes. A small concentration of free charge carries arising from the presence of Ge-vacancies was found not to affect significantly the neutron weighted phonon densities of states of GeTe. The spectral pattern changes qualitatively across the structural phase transition, but the local structure of GeTe remains hardly affected, as confirmed by the analysis of temperature dependence of the pairdistribution function obtained from ab initio molecular dynamics investigations. The present theoretical studies support in a wide extent our experimental observations and also those provided by local probe methods. |
BibTeX:
@article{Chatterji2019,
author = {Chatterji, T. and Rols, S. and Wdowik, U. D.},
title = {Dynamics of the phase-change material GeTe across the structural phase transition},
journal = {Front. Phys.},
year = {2019},
volume = {14},
number = {2},
pages = {23601},
url = {http://link.springer.com/10.1007/s11467-018-0864-1},
doi = {10.1007/s11467-018-0864-1}
}
|
| Czub J, Jamka W, Przewoźnik J, Zarzecka A, Hoser A, Wallacher D, Grimm N and Gondek (2019), "Structural peculiarities in the β phase of the La0.75Ce0.25Ni4.8Al0.2 deuterides", J. Alloys Compd., Jun, 2019. Vol. 788, pp. 533-540. |
| Abstract: In this contribution the structural, magnetic and sorption properties of the novel La0.75Ce0.25Ni4.8Al0.2 alloy and its deuterides are discussed. The collected data indicate good stability of the alloy during the cycle-life and thermal treatment tests. Particularly, the desorption pressure is almost constant versus the cycle number. The results of the in-situ neutron diffraction studies show the unusual behaviour of the deuterium rich β phase. Unexpectedly, the β phase belongs to the same P6/mmm space group as the hydrogen poor α phase. Moreover, the β phase behaves like a solid solution on the plateau of the pressure-composition-temperature (PCT) curve. The deuterium sites and their occupations in both α and β phases are determined from the neutron diffraction data, giving the first-hand insight into the mechanism of the PCT hysteresis. As far as the magnetic properties are concerned, cerium is trivalent in the investigated alloy. However, no magnetic ordering down to 3 K is observed. It can be concluded that the sorption properties of the crystal depend on the cerium valence, what distinguishes the alloy from the other compositions. |
BibTeX:
@article{Czub2019,
author = {Czub, J. and Jamka, W. and Przewoźnik, J. and Zarzecka, A. and Hoser, A. and Wallacher, D. and Grimm, N. and Gondek},
title = {Structural peculiarities in the β phase of the La0.75Ce0.25Ni4.8Al0.2 deuterides},
journal = {J. Alloys Compd.},
year = {2019},
volume = {788},
pages = {533--540},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838819307212},
doi = {10.1016/j.jallcom.2019.02.259}
}
|
| Dang N, Kozlenko D, Tran N, Lee B, Phan T, Madhogaria R, Kalappattil V, Yang D, Kichanov S, Lukin E, Savenko B, Czarnecki P, Tran T, Vo V, Thao L, Khan D, Tuan N, Jabarov S and Phan M (2019), "Structural, magnetic and electronic properties of Ti-doped BaFeO3- exhibiting colossal dielectric permittivity", J. Alloys Compd., Nov, 2019. Vol. 808, pp. 151760. |
| Abstract: We report a systematical investigation of the structural, magnetic, electronic, and dielectric properties of BaFe1-xTixO3-δ (x = 0.05, 0.10, 0.15 and 0.20) samples synthesized via the solid-state reaction method. Rietveld refinement using a combination of room-temperature X-ray (XRD) and neutron powder diffraction (NPD) data confirms single phases with a 6H-type structure for all the samples. X-ray absorption spectroscopy (XAS) study reveals a coexistence of Fe3+ and Fe4+, whose ratio remains almost unchanged with increasing Ti concentration. Magnetization measurements reveal a low-temperature inhomogeneous magnetic state with coexisting ferromagnetic (FM), AFM clusters and a paramagnetic phase. Moreover, magnetization of x = 0.10 shows a pinched hysteresis loop behavior, suggesting the coexistence of hard and soft FM phases in samples with high Ti concentrations. Low-temperature NPD measurements also confirm the absence of any long-range magnetic order in the samples. A colossal dielectric permittivity and two relaxation processes are observed for most of the studied samples. There is a change in electric conduction mechanism from the small polaron hopping to the Mott's variable-range hopping with increasing Ti concentration. |
BibTeX:
@article{Dang2019,
author = {Dang, N.T. and Kozlenko, D.P. and Tran, N. and Lee, B.W. and Phan, T.L. and Madhogaria, R.P. and Kalappattil, V. and Yang, D.S. and Kichanov, S.E. and Lukin, E.V. and Savenko, B.N. and Czarnecki, P. and Tran, T.A. and Vo, V.L. and Thao, L.T.P. and Khan, D.T. and Tuan, N.Q. and Jabarov, S.H. and Phan, M.H.},
title = {Structural, magnetic and electronic properties of Ti-doped BaFeO3- exhibiting colossal dielectric permittivity},
journal = {J. Alloys Compd.},
year = {2019},
volume = {808},
pages = {151760},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838819329937},
doi = {10.1016/j.jallcom.2019.151760}
}
|
| Fabrykiewicz P, Przeniosło R, Sosnowska I, Fauth F and Oleszak D (2019), "Verification of the de Wolff hypothesis concerning the symmetry of β-MnO2", Acta Crystallogr. Sect. A Found. Adv., Nov, 2019. Vol. 75(6), pp. 889-901. |
| Abstract: The symmetry lowering from tetragonal to orthorhombic is demonstrated using high-resolution diffraction and also justified by using the magnetic superspace groups formalism for the rutile-type compound β-MnO 2 . The (lower) orthorhombic symmetry is observed at temperatures both below and above the Néel temperature. The magnetic ordering of β-MnO 2 is of spin density type and not screw-type helical. The results support the de Wolff [ Acta Cryst. (1959), 12 , 341–345] hypothesis about the orthorhombic symmetry of β-MnO 2 . |
BibTeX:
@article{Fabrykiewicz2019,
author = {Fabrykiewicz, Piotr and Przeniosło, Radosław and Sosnowska, Izabela and Fauth, François and Oleszak, Dariusz},
title = {Verification of the de Wolff hypothesis concerning the symmetry of β-MnO 2},
journal = {Acta Crystallogr. Sect. A Found. Adv.},
year = {2019},
volume = {75},
number = {6},
pages = {889--901},
url = {http://scripts.iucr.org/cgi-bin/paper?S2053273319013408},
doi = {10.1107/S2053273319013408}
}
|
| Gadalińska E, Baczmański A, Wroński S, Kot P, Wroński M, Wróbel M, Scheffzük C, Bokuchava G and Wierzbanowski K (2019), "Neutron Diffraction Study of Phase Stresses in Al/SiCp Composite During Tensile Test", Met. Mater. Int., May, 2019. Vol. 25(3), pp. 657-668. |
| Abstract: The stress partitioning between phases, phase stress relaxation as well as origins of Al/SiCp composite strengthening are studied in the present work. In this aim, the measurements of lattice strains by neutron diffraction were performed in situ during tensile test up to sample fracture. The experimental results were compared with results of elastic–plastic self-consistent model. It was found that thermal origin phase stresses relax at the beginning of plastic deformation of Al/SiCp composite. The evolution of lattice strains in both phases can be correctly simulated by the elastic–plastic self-consistent model only if the relaxation of initial stresses is taken into account. A major role in the strengthening of the studied composite plays a transfer of stresses to the SiCp reinforcement, however the hardness of Al metal matrix is also important. |
BibTeX:
@article{Gadalinska2019,
author = {Gadalińska, Elżbieta and Baczmański, Andrzej and Wroński, Sebastian and Kot, Przemysław and Wroński, Marcin and Wróbel, Mirosław and Scheffzük, Christian and Bokuchava, Gizo and Wierzbanowski, Krzysztof},
title = {Neutron Diffraction Study of Phase Stresses in Al/SiCp Composite During Tensile Test},
journal = {Met. Mater. Int.},
year = {2019},
volume = {25},
number = {3},
pages = {657--668},
url = {http://link.springer.com/10.1007/s12540-018-00218-7},
doi = {10.1007/s12540-018-00218-7}
}
|
| Gawraczynski J, Kurzydłowski D, Ewings R, Bandaru S, Gadomski W, Mazej Z, Ruani G, Bergenti I, Jaron T, Ozarowski A, Lorenzana J and Grochala W (2019), "Silver route to cuprate analogs", Proc. Natl. Acad. Sci. U. S. A.. Vol. 116(5), pp. 1495-1500. |
| Abstract: The parent compound of high-Tc superconducting cuprates is a unique Mott insulator consisting of layers of spin- 1 /2 ions forming a square lattice and with a record high in-plane antiferromagnetic coupling. Compounds with similar characteristics have long been searched for without success. Here, we use a combination of experimental and theoretical tools to show that commercial AgF 2 is an excellent cuprate analog with remarkably similar electronic parameters to La 2 CuO 4 but larger buckling of planes. Two-magnon Raman scattering and inelastic neutron scattering reveal a superexchange constant reaching 70% of that of a typical cuprate. We argue that structures that reduce or eliminate the buckling of the AgF 2 planes could have an antiferromagnetic coupling that matches or surpasses the cuprates. |
BibTeX:
@article{Gawraczynski2019,
author = {Gawraczynski, J. and Kurzydłowski, D. and Ewings, R.A. and Bandaru, S. and Gadomski, W. and Mazej, Z. and Ruani, G. and Bergenti, I. and Jaron, T. and Ozarowski, A. and Lorenzana, J. and Grochala, W.},
title = {Silver route to cuprate analogs},
journal = {Proc. Natl. Acad. Sci. U. S. A.},
year = {2019},
volume = {116},
number = {5},
pages = {1495--1500},
doi = {10.1073/pnas.1812857116}
}
|
| Gil A, Baran S, Jaworska-Gołab T, Hoser A, Balińska A, Pavlyuk V and Szytuła A (2019), "Structural and magnetic properties of the RAl0.2Ge2 compounds (R = Tb, Dy, Ho, Er, Tm)", J. Alloys Compd., Jul, 2019. Vol. 792, pp. 142-150. |
| Abstract: The structural and magnetic properties of the RAl0.2Ge2 (R = Tb-Tm) germanides were studied by X-ray and neutron diffraction, scanning electron microscopy and magnetometric techniques. The compounds crystallize in the CeNiSi2-type crystal structure (space group Cmcm). Magnetic measurements reveal an antiferromagnetic ordering below TN equal to 38 K (R = Tb), 23 K (Dy), 9 K (Ho) and 6.5 K (Er), and no magnetic ordering in the Tm-compound down to 1.9 K. Based on the neutron diffraction data the magnetic structures can be described by the propagation vector k = (0.4714(2), 0, 0.3128(2)) for TbAl0.2Ge2 and k = (0.4858(5), 0, 0.3214(6)) for DyAl0.2Ge2 while in HoAl0.2Ge2 and ErAl0.2Ge2 a simple collinear antiferromagnetic ordering of the G-type was observed. The electronic structures of the title compounds were calculated using the tight-binding linear muffin-tin orbital (TB-LMTO) method. |
BibTeX:
@article{Gil2019,
author = {Gil, A. and Baran, S. and Jaworska-Gołab, T. and Hoser, A. and Balińska, A. and Pavlyuk, V. and Szytuła, A.},
title = {Structural and magnetic properties of the RAl0.2Ge2 compounds (R = Tb, Dy, Ho, Er, Tm)},
journal = {J. Alloys Compd.},
year = {2019},
volume = {792},
pages = {142--150},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838819311351},
doi = {10.1016/j.jallcom.2019.03.309}
}
|
| Golubev YA, Rozhkova NN, Kabachkov EN, Shul'ga YM, Natkaniec-Hołderna K, Natkaniec I, Antonets IV, Makeev BA, Popova NA, Popova VA and Sheka EF (2019), "sp amorphous carbons in view of multianalytical consideration: Normal, expeсted and new", J. Non. Cryst. Solids., Nov, 2019. Vol. 524, pp. 119608. |
| Abstract: sp2 Amorphous carbons are considered as objects of the modern nanotechnology. A particular set of the highest‑carbon-content sp2 species, two natural amorphous carbons (shungite carbon and antraxolite) as well as two engineered carbon blacks were subjected to analytical study by using a set of selected modern structural and compositional analytical techniques. The suggested approach occurred quite efficient and allowed disclosing a number of steady points that are common to the whole class of this carbon allotrope and are able to get a vision of atom-molecular representation of the solids. Among the commonalities observed, there are the following: i) sp2 Amorphous carbons are conglomerates of nanographites, basic structure units of which lay the foundation of the atom-molecular description of the solids. ii) The units represent framed graphene molecules of 1÷2 nm and of 1÷ (1÷3)*10 nm in size in the case of natural and engineered products, respectively. iii) The molecule framing, predominantly incomplete with respect to the number of vacant places, concerns only edge atoms and is implemented by the related chemical additives, such as hydrogen, oxygen, nitrogen, sulfur and halogens which are attached to the carbon core via chemical bonding. iv) Inelastic neutron scattering and X-ray photoelectron spectroscopy allow attributing the bonds to chemical compositions involving hydrogen and oxygen while quantum chemistry ensures reliable support. v) The basic structure units of sp2amorphous carbons are strongly radicalized due to which the latter acquire new properties, being the largest repository of stable radicals. |
BibTeX:
@article{Golubev2019,
author = {Golubev, Yevgeny A. and Rozhkova, Natalia N. and Kabachkov, Evgeniy N. and Shul'ga, Yuri M. and Natkaniec-Hołderna, Krystyna and Natkaniec, Ireneusz and Antonets, Igor V. and Makeev, Boris A. and Popova, Nadezhda A. and Popova, Vera A. and Sheka, Elena F.},
title = {sp amorphous carbons in view of multianalytical consideration: Normal, expeсted and new},
journal = {J. Non. Cryst. Solids},
year = {2019},
volume = {524},
pages = {119608},
url = {https://linkinghub.elsevier.com/retrieve/pii/S002230931930479X},
doi = {10.1016/j.jnoncrysol.2019.119608}
}
|
| Herbrych J, Heverhagen J, Patel N, Alvarez G, Daghofer M, Moreo A and Dagotto E (2019), "Novel Magnetic Block States in Low-Dimensional Iron-Based Superconductors", Phys. Rev. Lett., Jul, 2019. Vol. 123(2), pp. 027203. |
| Abstract: Inelastic neutron scattering recently confirmed the theoretical prediction of a ↑↑↓↓-magnetic state along the legs of quasi-one-dimensional iron-based ladders in the orbital-selective Mott phase (OSMP). We show here that electron doping of the OSMP induces a whole class of novel block states with a variety of periodicities beyond the previously reported π/2 pattern. We discuss the magnetic phase diagram of the OSMP regime that could be tested by neutrons once appropriate quasi-1D quantum materials with the appropriate dopings are identified. |
BibTeX:
@article{Herbrych2019,
author = {Herbrych, J. and Heverhagen, J. and Patel, N.D. and Alvarez, G. and Daghofer, M. and Moreo, A. and Dagotto, E.},
title = {Novel Magnetic Block States in Low-Dimensional Iron-Based Superconductors},
journal = {Phys. Rev. Lett.},
year = {2019},
volume = {123},
number = {2},
pages = {027203},
url = {https://link.aps.org/doi/10.1103/PhysRevLett.123.027203},
doi = {10.1103/PhysRevLett.123.027203}
}
|
| Hetmańczyk J, Hetmańczyk Ł and Gassowska K (2019), "Phase transition, structure and reorientational dynamics of H2O ligands and ReO4− anions in [Ba(H2O)3 ](ReO4)2 ⋅H2O". |
| Abstract: One, low-temperature phase transition (PT) was detected for [Ba(H 2 O) 3 ](ReO 4 ) 2 ⋅H 2 O, in the temperature range of 135–295 K by means of differential scanning calorimetry (DSC). The mean value of the PT temperature is T Ch = 275.0 K (onset on heating) and T Cc = 235.5 K (onset on cooling). Sharpness of the DSC peak as well as associated with this transformation hysteresis indicate that the detected PT is of the first-order type. X-ray single crystal diffraction (XRSCD) and neutron powder diffraction (ND) results showed that during the PT discovered at T Cc the crystal structure of the studied compound does not change. Vibrational and reorientational motions of H 2 O ligands and ReO 4− anions, in the high (I) and low (II) temperature phases, were investigated by Fourier transform middle-infrared and Raman light scattering spectroscopies (FT-MIR and RS). The temperature dependences of the full-width at half-maximum values (FWHM) of the band associated with δ(OReO) mode at 350 cm −1 in Raman spectra, suggests that the observed PT is not associated with a change of the perrhenate reorientational dynamics. However, the FT-MIR measurements showed that in the observed PT the reorientation dynamics of H 2 O ligands do contribute to the PT mechanism. Below the temperature of 225 K, a constant value of FWHM is observed, demonstrating the inhibition of reorientation of H 2 O molecules, and is associated only with so-called vibration relaxation. QENS measurements furnished evidence that H 2 O motion in high temperature phase (phase I) can be fairly accurately described by a simple model of 180° jumps around a twofold axis within a picosecond time scale with an assumption that three from four H 2 O molecules in [Ba(H 2 O) 3 ] 2+ ⋅H 2 O unit perform fast stochastic reorientations. Below PT QENS broadening is not observed. The QENS and IR methods clearly confirm that the observed PT is connected with slowing down of the reorientation dynamics of water molecules. The density functional theory plane wave calculations of the normal modes were performed in order to support band assignment. A good agreement between calculated and experimental data (IR and RS spectra) was obtained. |
BibTeX:
@misc{Hetmanczyk2019,
author = {Hetmańczyk, Joanna and Hetmańczyk, Łukasz and Gassowska, Katarzyna},
title = {Phase transition, structure and reorientational dynamics of H 2 O ligands and ReO 4− anions in [Ba(H 2 O) 3 ](ReO 4 ) 2 ⋅H 2 O},
booktitle = {J. Mol. Struct.},
year = {2019},
volume = {1188},
pages = {173--184},
doi = {10.1016/j.molstruc.2019.03.094}
}
|
| Jakubauskas D, Kowalewska Ł, Sokolova AV, Garvey CJ, Mortensen K, Jensen PE and Kirkensgaard JJK (2019), "Ultrastructural modeling of small angle scattering from photosynthetic membranes", Sci. Rep., Dec, 2019. Vol. 9(1), pp. 19405. |
| Abstract: The last decade has seen a range of studies using non-invasive neutron and X-ray techniques to probe the ultrastructure of a variety of photosynthetic membrane systems. A common denominator in this work is the lack of an explicitly formulated underlying structural model, ultimately leading to ambiguity in the data interpretation. Here we formulate and implement a full mathematical model of the scattering from a stacked double bilayer membrane system taking instrumental resolution and polydispersity into account. We validate our model by direct simulation of scattering patterns from 3D structural models. Most importantly, we demonstrate that the full scattering curves from three structurally typical cyanobacterial thylakoid membrane systems measured in vivo can all be described within this framework. The model provides realistic estimates of key structural parameters in the thylakoid membrane, in particular the overall stacking distance and how this is divided between membranes, lumen and cytoplasmic liquid. Finally, from fitted scattering length densities it becomes clear that the protein content in the inner lumen has to be lower than in the outer cytoplasmic liquid and we extract the first quantitative measure of the luminal protein content in a living cyanobacteria. |
BibTeX:
@article{Jakubauskas2019,
author = {Jakubauskas, Dainius and Kowalewska, Łucja and Sokolova, Anna V. and Garvey, Christopher J. and Mortensen, Kell and Jensen, Poul Erik and Kirkensgaard, Jacob J. K.},
title = {Ultrastructural modeling of small angle scattering from photosynthetic membranes},
journal = {Sci. Rep.},
year = {2019},
volume = {9},
number = {1},
pages = {19405},
url = {https://www.nature.com/articles/s41598-019-55423-0},
doi = {10.1038/s41598-019-55423-0}
}
|
| Jażdżewska M, Domin K, Śliwińska-Bartkowiak M, Beskrovnyi A, Chudoba D, Nagorna T, Ludzik K and Neov D (2019), "Structural properties of ice in confinement", J. Mol. Liq.. Vol. 283, pp. 167-173. |
| Abstract: Water confined in nanoscale exhibits unique structural properties compared to the bulk phase. The effects of confinement of water in carbon nanopores were investigated in this study using differential scanning calorimetry (DSC), dielectric spectroscopy (DS), and neutron diffraction (ND). The ice was confined in slit-shaped pores of activated carbon fibers (ACF) and cylindrical-shaped porous system (ordered carbon mesoporous structure - CMK-5) of different inner diameter. Melting behaviors of the confined ice were studied using DSC and DS methods, while ND technique was used to determine the structure of nanoconfined ice. ND measurements for D 2 O in different carbon nanopores were taken in a temperature range of 300 to 100 K. The results of the DS and ND studies showed the existence of hexagonal ice, Ih, and cubic ice, Ic at temperatures below the pores melting point. We have found that the content of confined hexagonal and cubic ice phases depend on the type of porous materials used in the confinement. Our results of the confined ice in the carbon nanopores revealed the features of stacking disordered ice I sd formed by disordered hexagonal and cubic ice layers, which has been recently reported in the literature. |
BibTeX:
@article{Jazdzewska2019,
author = {Jażdżewska, M. and Domin, K. and Śliwińska-Bartkowiak, M. and Beskrovnyi, A.I. and Chudoba, D.M. and Nagorna, T.V. and Ludzik, K. and Neov, D.S.},
title = {Structural properties of ice in confinement},
journal = {J. Mol. Liq.},
year = {2019},
volume = {283},
pages = {167--173},
doi = {10.1016/j.molliq.2019.03.080}
}
|
| Jażdżewska M, Śliwińska-Bartkowiak M, Domin K, Chudoba DM, Beskrovnyi AI, Neov DS and Gubbins KE (2019), "Structure of ice confined in carbon and silica nanopores", Bull. Mater. Sci., Aug, 2019. Vol. 42(4), pp. 184. |
| Abstract: In this work, water confined in silica and carbon nanopores has been examined. The purpose of this study is to describe the melting behaviour and structure of ice confined in silica nanopores, KIT-6 and ordered carbon nanopores, CMK-3, having pore diameters of 5.9 and 5.2 nm, respectively. To determine the melting temperature of ice inside the nanopores, we performed differential scanning calorimetry measurements of the systems studied. We found that the melting temperature of confined ice is reduced relative to the bulk melting point and this shift is 16 K for water confined in KIT-6 and 21 K for water confined in CMK-3. The structural properties of water at the interfaces were analysed by using the neutron diffraction method (ND). The ND measurements for all the systems studied, showed the features of both hexagonal ice, Ih, and cubic ice, Ic. However, we show that the ice confined in nanopores does not have a structure corresponding to the typical hexagonal form or the metastable cubic form. The ice confined in nanopores has a structure made up of cubic sequences interlaced with hexagonal sequences, which produce the stacking disordered ice (ice Isd). |
BibTeX:
@article{Jazdzewska2019a,
author = {Jażdżewska, Monika and Śliwińska-Bartkowiak, Małgorzata and Domin, Kamila and Chudoba, Dorota M and Beskrovnyi, Anatoly I and Neov, Dimitr S and Gubbins, Keith E},
title = {Structure of ice confined in carbon and silica nanopores},
journal = {Bull. Mater. Sci.},
year = {2019},
volume = {42},
number = {4},
pages = {184},
url = {http://link.springer.com/10.1007/s12034-019-1846-9},
doi = {10.1007/s12034-019-1846-9}
}
|
| Jin WT, Meven M, Sazonov AP, Demirdis S, Su Y, Xiao Y, Bukowski Z, Nandi S and Brückel T (2019), "Spin reorientation of the Fe moments in Eu0.5Ca0.5Fe2As2: Evidence for strong interplay of Eu and Fe magnetism", Phys. Rev. B., Apr, 2019. Vol. 99(14), pp. 140402. |
| Abstract: Using complementary polarized and unpolarized single-crystal neutron diffraction, we have investigated the temperature-dependent magnetic structures of Eu0.5Ca0.5Fe2As2. Upon 50% dilution of the Eu sites with isovalent Ca2+, the Eu sublattice is found to be still long-range ordered below TEu=10 K, in the A-type antiferromagnetic (AFM) structure. The moment size of Eu2+ spins is estimated to be as large as 6.74(4)μB at 2.5 K. The Fe sublattice undergoes a spin-density-wave transition at TSDW=192(2) K and displays an in-plane AFM structure above TEu. However, at 2.5 K, the Fe2+ moments are found to be ordered in a canted AFM structure with a canting angle of 14(4) out of the ab plane. The spin reorientation of Fe below the AFM ordering temperature of Eu provides direct evidence of a strong interplay between the two magnetic sublattices in Eu0.5Ca0.5Fe2As2. |
BibTeX:
@article{Jin2019,
author = {Jin, W. T. and Meven, M. and Sazonov, A. P. and Demirdis, S. and Su, Y. and Xiao, Y. and Bukowski, Z. and Nandi, S. and Brückel, Th.},
title = {Spin reorientation of the Fe moments in Eu0.5Ca0.5Fe2As2: Evidence for strong interplay of Eu and Fe magnetism},
journal = {Phys. Rev. B},
year = {2019},
volume = {99},
number = {14},
pages = {140402},
url = {https://link.aps.org/doi/10.1103/PhysRevB.99.140402},
doi = {10.1103/PhysRevB.99.140402}
}
|
| Jin WT, Qureshi N, Bukowski Z, Xiao Y, Nandi S, Babij M, Fu Z, Su Y and Brückel T (2019), "Spiral magnetic ordering of the Eu moments in EuNi2As2", Phys. Rev. B., Jan, 2019. Vol. 99(1), pp. 014425. |
| Abstract: The ground-state magnetic structure of EuNi2As2 was investigated by single-crystal neutron diffraction. At base temperature, the Eu2+ moments are found to form an incommensurate antiferromagnetic spiral-like structure with a magnetic propagation vector of k=(0,0,0.92). They align ferromagnetically in the ab plane with the moment size of 6.75(6) μB, but rotate spirally by 165.6(1) around the c axis from layer to layer. The magnetic order parameter in the critical region close to the ordering temperature TN=15 K shows critical behavior with a critical exponent of βEu=0.35(2), consistent with the three-dimensional Heisenberg model. Moreover, within the experimental uncertainty, our neutron data are consistent with a model in which the Ni sublattice is not magnetically ordered. |
BibTeX:
@article{Jin2019a,
author = {Jin, W. T. and Qureshi, N. and Bukowski, Z. and Xiao, Y. and Nandi, S. and Babij, M. and Fu, Z. and Su, Y. and Brückel, Th.},
title = {Spiral magnetic ordering of the Eu moments in EuNi2As2},
journal = {Phys. Rev. B},
year = {2019},
volume = {99},
number = {1},
pages = {014425},
url = {https://link.aps.org/doi/10.1103/PhysRevB.99.014425},
doi = {10.1103/PhysRevB.99.014425}
}
|
| Klimkowicz A, Cichy K, Chmaissem O, Dabrowski B, Poudel B, Świerczek K, Taddei KM and Takasaki A (2019), "Reversible oxygen intercalation in hexagonal Y0.7Tb0.3MnO3+δ: toward oxygen production by temperature-swing absorption in air", J. Mater. Chem. A. Vol. 7(6), pp. 2608-2618. |
| Abstract: The oxygen storage capacity, structure and thermodynamic stability were studied for hexagonal Y 0.7 Tb 0.3 MnO 3+δ in oxygen and air to assess its applicability for oxygen separation from air by a temperature-swing adsorption process. We show that large amounts of oxygen excess can be reversibly incorporated into and extracted from small particle-size samples of Y 0.7 Tb 0.3 MnO 3+δ prepared by sol-gel synthesis for fixed oxygen partial pressures. The hyperstoichiometric material, with δ ≥ 0.45 prepared in oxygen or high-pressure oxygen atmospheres, assumes a new hexagonal structure with interstitial oxygen defects near the nominally five coordinated Mn site as determined by neutron diffraction and supported by scanning and transmission electron microscopy. Thermogravimetric measurements demonstrate reversible intercalation of oxygen in a pure O 2 atmosphere at around 300 °C, but more importantly, also in air over a remarkably narrow temperature range of ∼20 °C, albeit producing smaller oxygen amounts δ ≤ 0.25. Comparison of samples' properties obtained by the sol-gel and solid-state synthesis methods confirms enhanced oxygen storage capacity and oxygen exchange kinetics for the small particle-size samples which exhibit larger specific surface areas. Sequential temperature-swing absorption and long-term annealing experiments demonstrate the high practical potential of Y 0.7 Tb 0.3 MnO 3 compounds for the industrial production of oxygen enriched gases by utilization of waste heat at 250-350 °C. |
BibTeX:
@article{Klimkowicz2019,
author = {Klimkowicz, Alicja and Cichy, Kacper and Chmaissem, Omar and Dabrowski, Bogdan and Poudel, Bisham and Świerczek, Konrad and Taddei, Keith M. and Takasaki, Akito},
title = {Reversible oxygen intercalation in hexagonal Y 0.7 Tb 0.3 MnO 3+: δ : toward oxygen production by temperature-swing absorption in air},
journal = {J. Mater. Chem. A},
year = {2019},
volume = {7},
number = {6},
pages = {2608--2618},
url = {http://xlink.rsc.org/?DOI=C8TA09235D},
doi = {10.1039/c8ta09235d}
}
|
| Kowalska-Mori A, Mamiya H, Ohnuma M, Ilavsky J, Gilbert E, Bazarnik P, Kitazawa H and Lewandowska M (2019), "Effect of post annealing on microstructure and mechanical properties in Ni-free N-containing ODS steel", Mater. Charact.. Vol. 153, pp. 339-347. |
| Abstract: The precipitation behavior of Y2O3 and MnO nanoparticles after isothermal treatment, in a Ni-free N-containing oxide dispersion strengthened (ODS) steel was studied by wide-angle X-ray scattering (WAXS), ultra-small-angle and small-angle X-ray scattering (USAXS/SAXS), small angle neutron scattering (SANS) and scanning transmission electron microscopy (STEM). Mechanical properties were investigated via tensile and micro-hardness testing. Additional precipitation occurred during annealing, in addition to the precipitates formed during sintering. The highest volume distribution of Y2O3, with average size of 6 nm, was determined by alloy contrast variation (ACV) analysis of SAXS and SANS for the sample annealed at 800 °C; this sample shows the highest hardness and ultimate tensile strength. Above that temperature, coarsening of both matrix and precipitates and depletion of nitrogen from matrix degraded the mechanical properties. The very fine nanoparticles and thermally induced dissolution of nitrogen influenced mechanical properties. |
BibTeX:
@article{Kowalska-Mori2019,
author = {Kowalska-Mori, A. and Mamiya, H. and Ohnuma, M. and Ilavsky, J. and Gilbert, E.P. and Bazarnik, P. and Kitazawa, H. and Lewandowska, M.},
title = {Effect of post annealing on microstructure and mechanical properties in Ni-free N-containing ODS steel},
journal = {Mater. Charact.},
year = {2019},
volume = {153},
pages = {339--347},
doi = {10.1016/j.matchar.2019.05.008}
}
|
| Krajewski M, Węglewski W, Bochenek K, Wysmołek A and Basista M (2019), "Optical measurements of thermal residual stresses in alumina reinforced with chromium", J. Appl. Phys., Apr, 2019. Vol. 125(13), pp. 135104. |
| Abstract: This work describes optical measurements of processing-induced thermal residual stresses in an alumina matrix reinforced with chromium particles. This ceramic-metal composite is manufactured by the powder metallurgy method comprising powder mixing in a planetary ball mill and consolidation by hot pressing. Two different chromium powders (5 μm and 45 μm mean particle size) are used, while the average alumina particle size is kept constant (1 μm). The residual stresses in aluminum oxide are determined by applying two optical methods: photoluminescence piezo-spectroscopy (PLPS) and Raman spectroscopy (RS). Both experimental techniques reveal a chromium size effect in the residual stress measurements. When the fine chromium powder (5 μm) is used, the average residual stress in the ceramic phase is tensile (unusual effect), whereas for the coarser chromium powder (45 μm) it becomes compressive. The PLPS measurements of the hydrostatic residual stress component in the ceramic phase yield the values of 0.290 and -0.130 GPa for samples with 5 μm and 45 μm chromium powders, respectively. In the RS experiments, the corresponding stress component in the alumina equals 0.351 GPa for the composite with 5 μm chromium and -0.158 GPa for that with 45 μm chromium powder. These values indicate that the residual stress in the alumina reinforced with 5 μm chromium is approximately twice higher than that in the alumina reinforced with 45 μm chromium. Finally, the validity of the results obtained with the optical techniques is confirmed by the neutron diffraction measurements. |
BibTeX:
@article{Krajewski2019,
author = {Krajewski, Marcin and Węglewski, Witold and Bochenek, Kamil and Wysmołek, Andrzej and Basista, Michał},
title = {Optical measurements of thermal residual stresses in alumina reinforced with chromium},
journal = {J. Appl. Phys.},
year = {2019},
volume = {125},
number = {13},
pages = {135104},
url = {http://aip.scitation.org/doi/10.1063/1.5083115},
doi = {10.1063/1.5083115}
}
|
| Krawczyk J, Massalska-Arodź M and Rozwadowski T (2019), "Low-temperature dynamics of (S)-4-(1-methylheptyloxy)-4ʹ-cyanobiphenyl (8*OCB) and (S)-4-(2-methylbutyl)-4ʹ-cyanobiphenyl (5*CB) in disordered crystalline and glassy phases", Liq. Cryst.. Vol. 46(1), pp. 94-101. |
| Abstract: The inelastic neutron scattering (INS) spectra were measured for two materials of chiral molecules: (S)-4-(1-methylheptyloxy)-4ʹ-cyanobiphenyl (8*OCB) and (S)-4-(2-methylbutyl)-4ʹ-cyanobiphenyl (5*CB), revealing solid state polymorphism with two partially disordered crystalline phases I and II and glassy state of liquid and of crystalline phase in each substance. The experiments were performed in the energy range up to 30 µeV in the temperature range from 4 to 35 K. For 8*OCB the elastic scans were measured as well up to 300 K illustrating well the phase diagram. For all solid phases of both substances in the µeV range of INS spectra, the existence of the excess density of vibrational states over that typical for fully ordered crystalline phases was evidenced. Contribution of this so-called boson peak occurred to be much larger in glass of isotropic phase than in the phase II and glass of phase I of 8*OCB, while for 5*CB it was larger in the phase I and glass of phase II than in glass of cholesteric phase. The quasi-elastic broadening of elastic peak corresponding to stochastic reorientations in the ns time scale was detected for both substances. Comparison of the results obtained for glassy and crystalline phases of 8*OCB and 5*CB compounds have been given and confronted with those obtained previously in meV energy range. |
BibTeX:
@article{Krawczyk2019,
author = {Krawczyk, J. and Massalska-Arodź, M. and Rozwadowski, T.},
title = {Low-temperature dynamics of (S)-4-(1-methylheptyloxy)-4ʹ-cyanobiphenyl (8*OCB) and (S)-4-(2-methylbutyl)-4ʹ-cyanobiphenyl (5*CB) in disordered crystalline and glassy phases},
journal = {Liq. Cryst.},
year = {2019},
volume = {46},
number = {1},
pages = {94--101},
doi = {10.1080/02678292.2018.1471748}
}
|
| Kuchin AG, Platonov SP, Iwasieczko W, Voronin VI and Gaviko VS (2019), "Effect of Chromium Substitution for Iron on the Magnetic and Structural Properties of (TmxPr1– x)2Fe17", Phys. Met. Metallogr., Dec, 2019. Vol. 120(12), pp. 1137-1144. |
| Abstract: Abstract: The (TmxPr1 – x)2Fe17 and (TmxPr1 – x)2Fe16.5Cr0.5 compounds crystallize with the formation of the rhombohedral Th2Zn17-type structure for the compositions with x = 0–0.4 and the hexagonal Th2Ni17-type structure for the compositions with x = 0.8–1 and x = 0.75–1, respectively. Both structures coexist in the (TmxPr1 – x)2Fe17 and (TmxPr1 – x)2Fe16.5Cr0.5 compounds with x = 0.5–0.75 and x = 0.5–0.6, respectively. The (TmxPr1 – x)2Fe17 compositions with 0 < x < 0.6 are ferrimagnets; at x = 0.6–1, additionally a high-temperature helical magnetic state is realized. The substitution of chromium for iron leads to the transformation of the helimagnet to ferrimagnet; in this case, the difference between the Curie temperatures of rhombohedral and hexagonal phases is unexpectedly high (25–28 К). For the composition with x = 0.8, the Curie and Néel temperatures and the ferrimagnet–helimagnet transformation temperature are minimum, and the microdeformations are maximum. The overlap of two peaks in –ΔSM(T), which correspond to the magnetic entropy change at two magnetic phase transformation temperatures, favors the realization of the higher cooling capacity of the two-phase compositions as compared to that of neighboring single-phase compositions. |
BibTeX:
@article{Kuchin2019,
author = {Kuchin, A. G. and Platonov, S. P. and Iwasieczko, W. and Voronin, V. I. and Gaviko, V. S.},
title = {Effect of Chromium Substitution for Iron on the Magnetic and Structural Properties of (TmxPr1– x)2Fe17},
journal = {Phys. Met. Metallogr.},
year = {2019},
volume = {120},
number = {12},
pages = {1137--1144},
url = {http://link.springer.com/10.1134/S0031918X19100065},
doi = {10.1134/S0031918X19100065}
}
|
| Lowe A, Tsyrin N, Chorążewski M, Zajdel P, Mierzwa M, Leão JB, Bleuel M, Feng T, Luo D, Li M, Li D, Stoudenets V, Pawlus S, Faik A and Grosu Y (2019), "Effect of Flexibility and Nanotriboelectrification on the Dynamic Reversibility of Water Intrusion into Nanopores: Pressure-Transmitting Fluid with Frequency-Dependent Dissipation Capability", ACS Appl. Mater. Interfaces., Oct, 2019. Vol. 11(43), pp. 40842-40849. |
| Abstract: In this article, the effect of a porous material's flexibility on the dynamic reversibility of a nonwetting liquid intrusion was explored experimentally. For this purpose, high-pressure water intrusion together with high-pressure in situ small-angle neutron scattering were applied for superhydrophobic grafted silica and two metal-organic frameworks (MOFs) with different flexibility [ZIF-8 and Cu2(tebpz) (tebpz = 3,3′,5,5′tetraethyl-4,4′-bipyrazolate)]. These results established the relation between the pressurization rate, water intrusion-extrusion hysteresis, and porous materials' flexibility. It was demonstrated that the dynamic hysteresis of water intrusion into superhydrophobic nanopores can be controlled by the flexibility of a porous material. This opens a new area of applications for flexible MOFs, namely, a smart pressure-transmitting fluid, capable of dissipating undesired vibrations depending on their frequency. Finally, nanotriboelectric experiments were conducted and the results showed that a porous material's topology is important for electricity generation while not affecting the dynamic hysteresis at any speed. |
BibTeX:
@article{Lowe2019,
author = {Lowe, Alexander and Tsyrin, Nikolay and Chorażewski, Mirosław and Zajdel, Paweł and Mierzwa, Michał and Leão, Juscelino B. and Bleuel, Markus and Feng, Tong and Luo, Dong and Li, Mian and Li, Dan and Stoudenets, Victor and Pawlus, Sebastian and Faik, Abdessamad and Grosu, Yaroslav},
title = {Effect of Flexibility and Nanotriboelectrification on the Dynamic Reversibility of Water Intrusion into Nanopores: Pressure-Transmitting Fluid with Frequency-Dependent Dissipation Capability},
journal = {ACS Appl. Mater. Interfaces},
year = {2019},
volume = {11},
number = {43},
pages = {40842--40849},
url = {https://pubs.acs.org/doi/10.1021/acsami.9b14031},
doi = {10.1021/acsami.9b14031}
}
|
| Lubecka E, Karczyńska A, Lipska A, Sieradzan A, Ziȩba K, Sikorska C, Uciechowska U, Samsonov S, Krupa P, Mozolewska M, Crivelli S and Liwo A (2019), "Evaluation of the scale-consistent UNRES force field in template-free prediction of protein structures in the CASP13 experiment", J. Mol. Graph. Model.. Vol. 92, pp. 154-166. |
| Abstract: The recent NEWCT-9P version of the coarse-grained UNRES force field for proteins, with scale-consistent formulas for the local and correlation terms, has been tested in the CASP13 experiment of the blind-prediction of protein structure, in the ab initio, contact-assisted, and data-assisted modes. Significant improvement of the performance has been observed with respect to the CASP11 and CASP12 experiments (by over 10 GDT_TS units for the ab initio mode predictions and by over 15 GDT_TS units for the contact-assisted prediction, respectively), which is a result of introducing scale-consistent terms and improved handling of contact-distance restraints. As in previous CASP exercises, UNRES ranked higher in the free modeling category than in the general category that included template based modeling targets. Use of distance restraints from the predicted contacts, albeit many of them were wrong, resulted in the increase of GDT_TS by over 8 units on average and introducing sparse restraints from small-angle X-ray/neutron scattering and chemical cross-link-mass-spectrometry experiments, and ambiguous restraints from nuclear magnetic resonance experiments has also improved the predictions by 8.6, 9.7, and 10.7 GDT_TS units on average, respectively. |
BibTeX:
@article{Lubecka2019,
author = {Lubecka, E.A. and Karczyńska, A.S. and Lipska, A.G. and Sieradzan, A.K. and Ziȩba, K. and Sikorska, C. and Uciechowska, U. and Samsonov, S.A. and Krupa, P. and Mozolewska, M.A. and Crivelli, S.N. and Liwo, A.},
title = {Evaluation of the scale-consistent UNRES force field in template-free prediction of protein structures in the CASP13 experiment},
journal = {J. Mol. Graph. Model.},
year = {2019},
volume = {92},
pages = {154--166},
doi = {10.1016/j.jmgm.2019.07.013}
}
|
| Mengucci P, Santecchia E, Gatto A, Bassoli E, Sola A, Sciancalepore C, Rutkowski B and Barucca G (2019), "Solid-State Phase Transformations in Thermally Treated Ti–6Al–4V Alloy Fabricated via Laser Powder Bed Fusion", Materials (Basel)., Sep, 2019. Vol. 12(18), pp. 2876. |
| Abstract: Laser Powder Bed Fusion (LPBF) technology was used to produce samples based on the Ti–6Al–4V alloy for biomedical applications. Solid-state phase transformations induced by thermal treatments were studied by neutron diffraction (ND), X-ray diffraction (XRD), scanning transmission electron microscopy (STEM) and energy-dispersive spectroscopy (EDS). Although, ND analysis is rather uncommon in such studies, this technique allowed evidencing the presence of retained β in α' martensite of the as-produced (#AP) sample. The retained β was not detectable by XRD analysis, nor by STEM observations. Martensite contains a high number of defects, mainly dislocations, that anneal during the thermal treatment. Element diffusion and partitioning are the main mechanisms in the α ↔ β transformation that causes lattice expansion during heating and determines the final shape and size of phases. The retained β phase plays a key role in the α' → β transformation kinetics. |
BibTeX:
@article{Mengucci2019,
author = {Mengucci, Paolo and Santecchia, Eleonora and Gatto, Andrea and Bassoli, Elena and Sola, Antonella and Sciancalepore, Corrado and Rutkowski, Bogdan and Barucca, Gianni},
title = {Solid-State Phase Transformations in Thermally Treated Ti–6Al–4V Alloy Fabricated via Laser Powder Bed Fusion},
journal = {Materials (Basel).},
year = {2019},
volume = {12},
number = {18},
pages = {2876},
url = {https://www.mdpi.com/1996-1944/12/18/2876},
doi = {10.3390/ma12182876}
}
|
| Munirathnappa A, Neuefeind J, Yanda P, Sundaresan A, Kityk I, Ozga K, Jedryka J, Poornesh P, Rao A and Sundaram N (2019), "Average Structure, Local Structure, Photoluminescence, and NLO Properties of Scheelite Type NaCe(WO4)2", Cryst. Growth Des.. Vol. 19(11), pp. 6082-6091. |
| Abstract: Phase pure nanoparticles of NaCe(WO4)2 green phosphor were synthesized via a template-free solvothermal method using water (NaCeW-a) and ethylene glycol (NaCeW-b) as reaction solvents. Rietveld refinements using powder neutron diffraction (NPD) data confirms that both NaCeW-a and NaCeW-b crystallize in the Scheelite-like tetragonal I41/a space group. However, local structure analysis using total scattering atomic pair distribution function (PDF) refinements in a shorter r' range (1.5 to 10 Å) established the noncentrosymmetric I4 space group where Na/CeO8 polyhedra are slightly distorted, distributed in 2b and 2d sites. The interesting observation of noncentrosymmetry locally in both NaCeW-a and NaCeW-b is supported by optical nonlinear second harmonic generation (SHG) measurements. Closer inspection of the scanning electron micrograms showed a distinct difference in the particle morphology as a function of reaction solvent. Observation of the +3 valence state of the cerium ion in NaCe(WO4)2 via X-ray photoelectron spectroscopy measurements was further corroborated by magnetic (VSM) measurements. In addition, both the samples emitted bright narrow green emission upon UV excitation with no considerable change in emission intensity with respect to solvent. Hence, the sharp green light emission and SHG properties make the NaCe(WO4)2 a potential candidate for solid state display and nonlinear optical applications. |
BibTeX:
@article{Munirathnappa2019,
author = {Munirathnappa, A.K. and Neuefeind, J.C. and Yanda, P. and Sundaresan, A. and Kityk, I.V. and Ozga, K. and Jedryka, J. and Poornesh, P. and Rao, A. and Sundaram, N.G.},
title = {Average Structure, Local Structure, Photoluminescence, and NLO Properties of Scheelite Type NaCe(WO4)2},
journal = {Cryst. Growth Des.},
year = {2019},
volume = {19},
number = {11},
pages = {6082--6091},
doi = {10.1021/acs.cgd.9b00041}
}
|
| Ortiz BR, Gomes LC, Morey JR, Winiarski M, Bordelon M, Mangum JS, Oswald IW, Rodriguez-Rivera JA, Neilson JR, Wilson SD, Ertekin E, McQueen TM and Toberer ES (2019), "New kagome prototype materials: Discovery of KV3, Sb5, RbV3, Sb5, and CsV3Sb5", Phys. Rev. Mater., Sep, 2019. Vol. 3(9), pp. 094407. |
| Abstract: In this work, we present our discovery and characterization of a new kagome prototype structure, KV3Sb5. We also present the discovery of the isostructural compounds RbV3Sb5 and CsV3Sb5. All materials exhibit a structurally perfect two-dimensional kagome net of vanadium. Density-functional theory calculations indicate that the materials are metallic, with the Fermi level in close proximity to several Dirac points. Powder and single-crystal syntheses are presented, with postsynthetic treatments shown to deintercalate potassium from single crystals of KV3Sb5. Considering the proximity to Dirac points, deintercalation provides a convenient means to tune the Fermi level. Magnetization measurements indicate that KV3Sb5 exhibits behavior consistent with a the Curie-Weiss model at high temperatures, although the effective moment is low (0.22μB per vanadium ion). An anomaly is observed in both magnetization and heat capacity measurements at 80 K, below which the moment is largely quenched. Elastic neutron scattering measurements find no obvious evidence of long-range or short-range magnetic ordering below 80 K. The possibility of an orbital-ordering event is considered. Single-crystal resistivity measurements show the effect of deintercalation on the electron transport and allow estimation of the Kadowaki-Woods ratio in KV3Sb5. We find that A/γ2∼61μOhm cm molFU2K2J-2, suggesting that correlated electron transport may be possible. KV3Sb5 and its cogeners RbV3Sb5 and CsV3Sb5 represent a new family of kagome metals, and our results demonstrate that they deserve further study as potential model systems. |
BibTeX:
@article{Ortiz2019,
author = {Ortiz, Brenden R. and Gomes, Lídia C. and Morey, Jennifer R. and Winiarski, Michal and Bordelon, Mitchell and Mangum, John S. and Oswald, Iain W.H. and Rodriguez-Rivera, Jose A. and Neilson, James R. and Wilson, Stephen D. and Ertekin, Elif and McQueen, Tyrel M. and Toberer, Eric S.},
title = {New kagome prototype materials: Discovery of KV3Sb5,RbV3Sb5, and CsV3Sb5},
journal = {Phys. Rev. Mater.},
year = {2019},
volume = {3},
number = {9},
pages = {094407},
url = {https://link.aps.org/doi/10.1103/PhysRevMaterials.3.094407},
doi = {10.1103/PhysRevMaterials.3.094407}
}
|
| Pärschke EM, Wang Y, Moritz B, Devereaux TP, Chen C-C and Wohlfeld K (2019), "Numerical investigation of spin excitations in a doped spin chain", Phys. Rev. B., May, 2019. Vol. 99(20), pp. 205102. |
| Abstract: We study the doping evolution of spin excitations in a one-dimensional (1D) Hubbard model and its downfolded spin Hamiltonians, by using exact diagonalization combined with cluster perturbation theory. In all models we observe hardening (softening) of spin excitations upon electron (hole) doping, which are reminiscent of recent experiments on two-dimensional (2D) cuprate materials. We also find that the three-site and even higher-order terms are crucial for the low-energy effective spin models to reproduce the magnetic spectra of doped Hubbard systems at a quantitative level. To interpret the numerical results, we further employ a strong coupling slave-boson mean-field theory. The mean-field theory provides an intuitive understanding of the overall compact support of dynamic spin structure factors, including the shift of zero-energy modes and change of spin excitation bandwidth with doping. Our results can serve as predictive benchmarks for future inelastic x-ray or neutron scattering experiments on doped 1D antiferromagnetic Mott insulators. |
BibTeX:
@article{Parschke2019,
author = {Pärschke, Ekaterina M. and Wang, Yao and Moritz, Brian and Devereaux, Thomas P. and Chen, Cheng-Chien and Wohlfeld, Krzysztof},
title = {Numerical investigation of spin excitations in a doped spin chain},
journal = {Phys. Rev. B},
year = {2019},
volume = {99},
number = {20},
pages = {205102},
url = {https://link.aps.org/doi/10.1103/PhysRevB.99.205102},
doi = {10.1103/PhysRevB.99.205102}
}
|
| Penc B, Baran S, Hoser A and Szytuła A (2019), "Magnetic properties and magnetic structures of Nd2TGe6 (T = Ni, Cu)", Phase Transitions., Dec, 2019. Vol. 92(12), pp. 1118-1126. |
| Abstract: The magnetic properties and magnetic structures of Nd2TGe6 (T = Ni and Cu) were studied by magnetometric and neutron diffraction measurements. Both compounds have an orthorhombic crystal structure of the Ce2CuGe6-type and are antiferromagnetic with the Néel temperatures of 6.4 K (Nd2NiGe6) and 9.8 K (Nd2CuGe6). Based on the neutron diffraction data the magnetic structures were determined. In the investigated compounds all magnetic moments are localized on the Nd atoms and form a collinear commensurate magnetic structure with the magnetic unit cell equal to the crystal one. The moments are parallel to the b-axis (T = Ni) or to the c-axis (T = Cu). The obtained magnetic structures are discussed on the basis of competition between the RKKY-type interactions and influence of Crystalline Electric Field (CEF). |
BibTeX:
@article{Penc2019,
author = {Penc, Bogusław and Baran, Stanisław and Hoser, Andreas and Szytuła, Andrzej},
title = {Magnetic properties and magnetic structures of Nd2TGe6 (T = Ni, Cu)},
journal = {Phase Transitions},
year = {2019},
volume = {92},
number = {12},
pages = {1118--1126},
url = {https://www.tandfonline.com/doi/full/10.1080/01411594.2019.1679368},
doi = {10.1080/01411594.2019.1679368}
}
|
| Penc B, Baran S, Hoser A and Szytuła A (2019), "Magnetic properties and magnetic structures of R2TGe6 (T = Ni, Cu; R = Tb, Ho and Er)", J. Alloys Compd., Sep, 2019. Vol. 803, pp. 307-313. |
| Abstract: The magnetic properties and magnetic structures of the R2TGe6 compounds (T = Ni and Cu, R = Tb, Ho and Er) were studied by magnetometric and neutron diffraction measurements. All compounds have an orthorhombic crystal structure of the Ce2CuGe6-type and are antiferromagnetic with the Néel temperatures ranging from 6 K for Er2CuGe6 up to 42 K for Tb2NiGe6. Based on the neutron diffraction data the magnetic structures were determined for R2NiGe6 (R = Tb, Er) and R2CuGe6 (R = Ho, Er). In these compounds the magnetic moments localized on the rare earth element form a collinear commensurate magnetic structure. The magnetic unit cell is equal to the crystal one in R2NiGe6 (R = Tb, Er) while it is doubled along the a-axis (propagation vector k = (½, 0, 0)) in R2CuGe6 (R = Ho and Er). The obtained magnetic structures are discussed on the basis of competition between the RKKY-type interactions and influence of Crystalline Electric Field (CEF). |
BibTeX:
@article{Penc2019a,
author = {Penc, Bogusław and Baran, Stanisław and Hoser, Andreas and Szytuła, Andrzej},
title = {Magnetic properties and magnetic structures of R2TGe6 (T = Ni, Cu; R = Tb, Ho and Er)},
journal = {J. Alloys Compd.},
year = {2019},
volume = {803},
pages = {307--313},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838819320924},
doi = {10.1016/j.jallcom.2019.06.027}
}
|
| Pugaczowa-Michalska M (2019), "Magnetic moment of Mn in disordered Pd2MnGe Heusler alloy as studied by CPA and supercell modelling", J. Magn. Magn. Mater., Dec, 2019. Vol. 491, pp. 165638. |
| Abstract: The neutron-scattering measurements and the observation of hyperfine interaction of nuclear moments in Pd2MnGe alloy have prompted a study of disorder in this compound by the density functional theory methods. Two approaches: the coherent-potential approximation (CPA) and supercell modelling were used to gain microscopic insight into the electronic and magnetic properties of disordered Pd2MnGe. The influence of disorder between Pd and Mn sublattices in Pd2MnGe on the magnetic moment of Mn atoms is discussed. The presented CPA studies have shown that the small disorder in Pd2MnGe (between the Pd-Mn sublattices of the L21 structure) does not well describe the experimental evidence of antiparallel alignment of magnetic moment of Mn at positions (A,C) and B positions. However, the appearance of antiparallel moment of Mn at positions A and B was predicted for the Pd2MnGe in the frames of 128-atoms supercell calculations. The generalized gradient approximation (GGA) has been the main basis for the presented supercell first-principles electronic structure calculations. The magnetic moment of Mn(A,C) is found to be small and negative value of −0.177 µB. The values of magnetic moment of Mn(B) are between 3.6 µB and 3.72 µB. The results obtained for the supercell calculations are consistent with available experiments in the literature. The results of presented calculations in the supercell approach have shown that the disordered Pd2MnGe can be predicted as a mixture of several supercells. |
BibTeX:
@article{Pugaczowa-Michalska2019,
author = {Pugaczowa-Michalska, M.},
title = {Magnetic moment of Mn in disordered Pd2MnGe Heusler alloy as studied by CPA and supercell modelling},
journal = {J. Magn. Magn. Mater.},
year = {2019},
volume = {491},
pages = {165638},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0304885319308285},
doi = {10.1016/j.jmmm.2019.165638}
}
|
| Rajendran V, Leśniewski T, Mahlik S, Grinberg M, Leniec G, Kaczmarek S, Pang W-K, Lin Y-S, Lu K-M, Lin C-M, Hu S-F and Liu R-S (2019), "Ultra-Broadband Phosphors Converted Near-Infrared Light Emitting Diode with Efficient Radiant Power for Spectroscopy Applications", ACS Photonics. Vol. 6(12), pp. 3215-3224. |
| Abstract: Narrowing the size of near-infrared (NIR) spectrometers has gained substantial interest among researchers in both scientific and nonscientific communities due to the inherent usage in the nondestructive investigations, especially for foodstuff evaluation and human health monitoring. The immense size and deteriorating accessibility of traditional NIR light sources make the phosphor-converted NIR light-emitting diode (pc-NIR LED) with high radiant flux an alternative growing light source. In this work, the crystal structure of La3GaGe5O16 is solved for the actual crystallographic sites through a joint Rietveld refinement tool (X-ray diffraction and high-resolution neutron powder diffraction) and reporting for the ultrabroadband NIR luminescence (650-1050 nm) by doping with Cr3+ with the hyper-radiant power of 43.1 mW. It is noteworthy that the possible benchmarking radiant power of 65.2 mW is achieved by the chemical substitution of Gd3+ and Sn4+. The presence of multiple excited behavior states (multiple luminescent centers) of Cr3+ due to its intermediate crystal field resulted in broadening of the emission spectrum along with increased intensity. The nonexponential decay character of the R-line and broadband luminescence further confirms the observation of the multiple excited state. The findings of this work are discussed based on structural characterization and spectroscopic studies at different measurement environments, and the potentials of the phosphors are also demonstrated by the prototype pc-NIR LED packaging. |
BibTeX:
@article{Rajendran2019,
author = {Rajendran, V. and Lesniewski, T. and Mahlik, S. and Grinberg, M. and Leniec, G. and Kaczmarek, Sł.M. and Pang, W.-K. and Lin, Y.-S. and Lu, K.-M. and Lin, C.-M. and Hu, S.-F. and Liu, R.-S.},
title = {Ultra-Broadband Phosphors Converted Near-Infrared Light Emitting Diode with Efficient Radiant Power for Spectroscopy Applications},
journal = {ACS Photonics},
year = {2019},
volume = {6},
number = {12},
pages = {3215--3224},
doi = {10.1021/acsphotonics.9b01086}
}
|
| Rok M, Bator G, Zarychta B, Dziuk B, Repeć J, Medycki W, Zamponi M, Usevičius G, Šimėnas M and Banys J (2019), "Isostructural phase transition, quasielastic neutron scattering and magnetic resonance studies of a bistable dielectric ion-pair crystal [(CH3)2NH2]2 KCr(CN)6", Dalt. Trans.. Vol. 48(13), pp. 4190-4202. |
| Abstract: Ferroelastic phase transition in novel HOIP crystal with dielectric switchable properties. |
BibTeX:
@article{Rok2019,
author = {Rok, M. and Bator, G. and Zarychta, B. and Dziuk, B. and Repeć, J. and Medycki, W. and Zamponi, M. and Usevičius, G. and Šimėnas, M. and Banys, J.},
title = {Isostructural phase transition, quasielastic neutron scattering and magnetic resonance studies of a bistable dielectric ion-pair crystal [(CH 3 ) 2 NH 2 ] 2 KCr(CN) 6},
journal = {Dalt. Trans.},
year = {2019},
volume = {48},
number = {13},
pages = {4190--4202},
url = {http://xlink.rsc.org/?DOI=C8DT05082A},
doi = {10.1039/C8DT05082A}
}
|
| Rok M, Bator G, Zarychta B, Dziuk B, Skałecki DK, Medycki W and Zamponi M (2019), "Screening Ferroelastic Transitions in Switchable Cyano-Bridged Perovskites: [(CH3)2C(NH2)2]2[KM(CN)6], M = Cr3+, Fe3+, Co3+. Crystal Structure Characterization, Dielectric Properties, 1H NMR, and Quasielastic Neutron Scattering Studies", Cryst. Growth Des., Aug, 2019. Vol. 19(8), pp. 4526-4537. |
| Abstract: Here we report the dynamics of organic cations as guest molecules in the novel perovskite host framework. The novel switchable crystals from the coordination family [CH3C(NH2)2]2[KB″(CN)6] were constructed by employing acetamidinium cations (ACE = [CH3C(NH2)2]) as A-site and B″: Cr3+, Fe3+, Co3+ in the inorganic cage. The molecular motion of ACE+ as well as the effect of the trivalent metallic cation type on two-step transitions were studied using a combination of experimental methods: (i) X-ray diffraction experiments, (ii) thermal analysis, (iii) dielectric and electric studies, (iv) optical observations, (v) 1H NMR spectroscopy, and (vi) quasielastic neutron scattering (QENS). On the basis of the X-ray analysis, transitions occur from a frozen-order phase (III, monoclinic, C2/m) to an in-plane rotational disorder state (II, trigonal, R3 m) and to a melt-like disorder one (I, cubic, Fm3 m). A markedly temperature-dependent dielectric constant indicates the tunable and switchable properties of all complexes. The QENS, as well as 1H NMR spectroscopy, were applied to measure the dynamics of the organic cations residing in the inorganic framework. The ferroelastic nature of the phases III and II were proven based on the polarized light microscopy photographs. Also, the modified equation of the tolerance factor t was used to estimate the theoretical phase transition temperatures for a crystal with Mn3+ |
BibTeX:
@article{Rok2019a,
author = {Rok, Magdalena and Bator, Grażyna and Zarychta, Bartosz and Dziuk, Błażej and Skałecki, Damian K. and Medycki, Wojciech and Zamponi, Michaela},
title = {Screening Ferroelastic Transitions in Switchable Cyano-Bridged Perovskites: [CH3C(NH2)2]2[KM(CN)6], M = Cr3+, Fe3+, Co3+. Crystal Structure Characterization, Dielectric Properties, 1H NMR, and Quasielastic Neutron Scattering Studies},
journal = {Cryst. Growth Des.},
year = {2019},
volume = {19},
number = {8},
pages = {4526--4537},
url = {https://pubs.acs.org/doi/10.1021/acs.cgd.9b00298},
doi = {10.1021/acs.cgd.9b00298}
}
|
| Santecchia E, Gatto A, Bassoli E, Denti L, Rutkowski B, Mengucci P and Barucca G (2019), "Precipitates formation and evolution in a Co-based alloy produced by powder bed fusion", J. Alloys Compd.. Vol. 797, pp. 652-658. |
| Abstract: Metal additive manufacturing is strongly employed in aerospace and biomedical applications, whose high degree of customization and low production volumes are the main characteristics. Cobalt-based alloys have been widely used for dental prosthesis and can be produced via metal additive manufacturing, or rather powder bed fusion, in a more convenient way compared to traditional manufacturing techniques. In the present paper, a comprehensive study of the tight correlation between the microstructure and the static mechanical properties of Co-Cr-Mo-W samples produced by powder bed fusion, is reported. In particular, the formation of precipitates during the sintering process is observed, and the evolution of their size, shape and frequency due to post-processing and to a heat-treatment typical of dental applications, is exhaustively studied. By coupling different characterization techniques such as scanning transmission electron microscopy and small-angle neutron scattering, it was possible to correlate the ductility degradation of the samples with the formation and growth of coarse and elongated precipitates. |
BibTeX:
@article{Santecchia2019,
author = {Santecchia, E. and Gatto, A. and Bassoli, E. and Denti, L. and Rutkowski, B. and Mengucci, P. and Barucca, G.},
title = {Precipitates formation and evolution in a Co-based alloy produced by powder bed fusion},
journal = {J. Alloys Compd.},
year = {2019},
volume = {797},
pages = {652--658},
doi = {10.1016/j.jallcom.2019.05.169}
}
|
| Sheka E, Hołderna-Natkaniec K, Natkaniec I, Krawczyk J, Golubev Y, Rozhkova N, Kim V, Popova N and Popova V (2019), "Computationally Supported Neutron Scattering Study of Natural and Synthetic Amorphous Carbons", J. Phys. Chem. C. Vol. 123(25), pp. 15841-15850. |
| Abstract: Neutron powder diffraction and inelastic neutron scattering (INS) were used to determine the structure and hydrogen content of basic structure units (BSUs) of sp2 amorphous carbons at the atomic level. A comparative study of two natural (shungite carbon and antraxolite) and two synthetic (carbon blacks) species of the highest-rank carbonization revealed nanosize stack structure of all samples. The stacks are formed by BSUs representing framed graphene molecules (graphene oxyhydrides) of ∼2.5 nm lateral dimension. The INS study showed the presence of hydrogen atoms in the BSU framing area as well as of adsorbed water in the sample pores configured by BSU stacks. Simulated INS spectra of adsorbed water showed its monolayer disposition within the pores. BSU INS spectra were simulated for a set of particular models simulating H-standard features of the INS spectra of graphene-based species, in general, and BSU hydrogen component of the studied samples, in particular. Simulations were performed in the framework of both spin-independent (density functional theory) and spin-dependent (unrestricted Hartree-Fock) molecular vibrational dynamics. The obtained results allowed a reliable presentation of the hydrogeneous component of the BSU atomic structure and proposing a specific INS classification of sp2 amorphous carbons with respect to their hydrogeneousness. |
BibTeX:
@article{Sheka2019,
author = {Sheka, E.F. and Hołderna-Natkaniec, K. and Natkaniec, I. and Krawczyk, J.X. and Golubev, Y.A. and Rozhkova, N.N. and Kim, V.V. and Popova, N.A. and Popova, V.A.},
title = {Computationally Supported Neutron Scattering Study of Natural and Synthetic Amorphous Carbons},
journal = {J. Phys. Chem. C},
year = {2019},
volume = {123},
number = {25},
pages = {15841--15850},
doi = {10.1021/acs.jpcc.9b03675}
}
|
| Shpotyuk O (2019), "Critical remark on the FSDP-related correlations in chalcogenide glasses as treated in the paper [Alekberov RI, Isayev AI, Mekhtiyeva SI, Fábián M. Local structures and optical properties of As-Se-Te(S) chalcogenide glasses. Phys B: Condens Matter 2018; 5", Results Phys.. Vol. 12, pp. 2098-2099. |
| Abstract: In the paper [Phys. B 550 (2018) 367–375], Alekberov, Isayev, Mekhtiyeva and Fábián have performed very erroneous calculation on diameter of voids responsible for the first sharp diffraction peak (FSDP) in neutron diffraction patterns of As 2 Se 3 -based glasses. The authors used wrong relation for the FSDP position taken from entirely speculative assertion presented by Kavetskyy in [Semicond. Phys. Quantum Electron. Optoelectron. 16 (2013) 136–139], assuming unreasonable equivalence between chemistry of chalcogenide glasses and typical polymers. In this communication, the deep reason for this incorrectness was disclosed, and alternative variant to estimate diameters of interstitial voids responsible for the FSDP in As 2 Se 3 -based glasses was presented. |
BibTeX:
@article{Shpotyuk2019,
author = {Shpotyuk, O.},
title = {Critical remark on the FSDP-related correlations in chalcogenide glasses as treated in the paper [Alekberov RI, Isayev AI, Mekhtiyeva SI, Fábián M. Local structures and optical properties of As-Se-Te(S) chalcogenide glasses. Phys B: Condens Matter 2018; 5},
journal = {Results Phys.},
year = {2019},
volume = {12},
pages = {2098--2099},
doi = {10.1016/j.rinp.2019.02.056}
}
|
| Sirovica S, Skoda M, Podgorski M, Thompson P, Palin W, Guo Y, Smith A, Dewan K, Addison O and Martin R (2019), "Structural Evidence That the Polymerization Rate Dictates Order and Intrinsic Strain Generation in Photocured Methacrylate Biomedical Polymers", Macromolecules. Vol. 52(14), pp. 5377-5388. |
| Abstract: The influence of reaction rate on the evolving polymer structure of photo-activated dimethacrylate biomedical resins was investigated using neutron and in situ synchrotron X-ray scattering with simultaneous Fourier-transform-near-infrared spectroscopy. Previous studies have correlated the degree of reactive group conversion with mechanical properties, but the impact of polymerization rate on the resultant polymer structure is unknown. Here, we demonstrate that the medium-range structural order at the functional end groups of these materials is dependent on the reaction rate. Accelerating polymerization increases correlation lengths in the methacrylate end groups but reduces the medium-range structural order per converted vinyl bond when compared with more slowly polymerized systems. At faster rates of polymerization, the conformation of atoms at the reacting end group can become fixed into the polymer structure at the onset of autodeceleration, storing residual strain. Neutron scattering confirms that the structural differences observed are reproduced at longer length scales. This effect is not as prominent in systems polymerized at slower rates despite similar final degrees of reactive group conversion. Results suggest that current interpretations of these materials, which extrapolate mechanical properties from conversion, may be incomplete. Accelerating polymerization can introduce structural differences, which will dictate residual strain and may ultimately explain the discrepancies in the predictive modeling of the mechanical behavior of these materials using conventional techniques. |
BibTeX:
@article{Sirovica2019,
author = {Sirovica, S. and Skoda, M.W.A. and Podgorski, M. and Thompson, P.B.J. and Palin, W.M. and Guo, Y. and Smith, A.J. and Dewan, K. and Addison, O. and Martin, R.A.},
title = {Structural Evidence That the Polymerization Rate Dictates Order and Intrinsic Strain Generation in Photocured Methacrylate Biomedical Polymers},
journal = {Macromolecules},
year = {2019},
volume = {52},
number = {14},
pages = {5377--5388},
doi = {10.1021/acs.macromol.9b00133}
}
|
| Skokowski P, Synoradzki K and Toliński T (2019), "Comprehensive studies of the transformation between antiferromagnetic CeCoGe3 and heavy fermion CeFeGe3 compounds", J. Alloys Compd., Nov, 2019. Vol. 810, pp. 151850. |
| Abstract: We report extensive studies of a series of alloys CeCo1−xFexGe3 in which suppression of the antiferromagnetic order in CeCoGe3 with temperature decreasing to 0 K was observed as a result of substitution of Co with Fe. Unusual temperature dependences were observed of a number of parameters characterizing these compounds: magnetic susceptibility, specific heat, electrical resistivity, magnetoresistance and thermoelectric power, which may be indication towards non-Fermi liquid behaviour connected with quantum critical point (QCP) or can result from a quantum Griffiths phase (QGP) formation. The three AFM transitions found previously for a single crystal CeCoGe3 compound were also detected in our high quality polycrystalline samples, including the case of x>0. All measurements, especially those of magnetocaloric effect (MCE), suggest that for samples with x≥0.1 the contribution of ferromagnetic component, known already for x=0 from the neutron diffraction experiments, increases significantly, with the AFM contribution still present at low temperatures. Finally, the use of different complementary methods enabled construction of a comprehensive magnetic phase diagram of CeCo1−xFexGe3 system. |
BibTeX:
@article{Skokowski2019,
author = {Skokowski, P. and Synoradzki, K. and Toliński, T.},
title = {Comprehensive studies of the transformation between antiferromagnetic CeCoGe3 and heavy fermion CeFeGe3 compounds},
journal = {J. Alloys Compd.},
year = {2019},
volume = {810},
pages = {151850},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838819330890},
doi = {10.1016/j.jallcom.2019.151850}
}
|
| Stelmakh S, Skrobas K, Gierlotka S and Palosz B (2019), "Atomic structure of nanodiamond and its evolution upon annealing up to 1200 °C: Real space neutron diffraction analysis supported by MD simulations", Diam. Relat. Mater.. Vol. 93, pp. 139-149. |
| Abstract: Lattice strain, crystallite shape and the crystallite size distribution in nanocrystalline diamond were determined from powder diffraction data. The data were analyzed by the direct space PDF method in combination with Molecular Dynamics simulations. Experimental Pair Distribution Functions were obtained from the large Q neutron diffraction data. Lattice strains were determined by comparison of the atomic pair distances at different length scales. The experimental pair-distance data were matched against the Molecular Dynamics models of diamond nanograins. Lattice relaxation at the surface and in the bulk of the simulated nanodiamond grains varied with their shape and size. Comparison of the model data to the experimentally determined strain characteristics yielded accurate information on the structure of the actual nanodiamond powders. In the as-synthesized nanodiamond the grains are polyhedrons predominantly terminated by (100) and (111) surfaces. Upon annealing the (111) surfaces with one dangling bond per atom graphitize and transform into surfaces with three dangling bond per atom. In the samples annealed at 1200 °C all grains are octahedrons terminated only by three dangling bond (111) surfaces. The mechanism of the atom rearrangement during the transformation of the (111) diamond surface into a graphite double-sheet was proposed. |
BibTeX:
@article{Stelmakh2019,
author = {Stelmakh, S. and Skrobas, K. and Gierlotka, S. and Palosz, B.},
title = {Atomic structure of nanodiamond and its evolution upon annealing up to 1200 °C: Real space neutron diffraction analysis supported by MD simulations},
journal = {Diam. Relat. Mater.},
year = {2019},
volume = {93},
pages = {139--149},
doi = {10.1016/j.diamond.2019.02.004}
}
|
| Szytuła A, Baran S, Penc B, Hoser A and Dyakonov V (2019), "Magnetic order in quaternary nimnge: T (t = cr, ti) compounds", In Solid State Phenom.. Vol. 289 SSP, pp. p 156-163. |
| Abstract: The work reports the results of neutron diffraction measurements of NiMnGe:T systems where T is Cr or Ti. All investigated compounds have the helicoidal magnetic structure with the propagation vector k = (ka,0,0). The values of the ka component decrease with increasing Cr content and increase with increasing Ti content. For all compounds, except the sample with x = 0.18 in Crsystem, the helicoidal order is stable up to the Néel temperature. The obtained data are analysed with a simple model in which the magnetic interactions are described by two exchange integrals J1 > 0 for first and J2 < 0 for second neighbouring moments. This model reproduces the different dependencies of the helicoidal propagation vector ka component in different systems. |
BibTeX:
@inproceedings{Szytua2019,
author = {Szytuła, Andrzej and Baran, Stanisław and Penc, Bogusław and Hoser, Andreas and Dyakonov, Vladimir},
title = {Magnetic order in quaternary nimnge: T (t = cr, ti) compounds},
booktitle = {Solid State Phenom.},
year = {2019},
volume = {289 SSP},
pages = {p 156--163},
doi = {10.4028/www.scientific.net/SSP.289.156}
}
|
| Taube M, Pietralik Z, Szymanska A, Szutkowski K, Clemens D, Grubb A and Kozak M (2019), "The domain swapping of human cystatin C induced by synchrotron radiation", Sci. Rep., Jun, 2019. Vol. 9(1), pp. 8548. |
| Abstract: Domain swapping is observed for many proteins with flexible conformations. This phenomenon is often associated with the development of conformational diseases. Importantly, domain swapping has been observed for human cystatin C (HCC), a protein capable of forming amyloid deposits in brain arteries. In this study, the ability of short exposure to high-intensity X-ray radiation to induce domain swapping in solutions of several HCC variants (wild-type HCC and V57G, V57D, V57N, V57P, and L68V mutants) was determined. The study was conducted using time-resolved small-angle X-ray scattering (TR-SAXS) synchrotron radiation. The protein samples were also analysed using small-angle neutron scattering and NMR diffusometry. Exposing HCC to synchrotron radiation (over 50 ms) led to a gradual increase in the dimeric fraction, and for exposures longer than 150 ms, the oligomer fraction was dominant. In contrast, the non-irradiated protein solutions, apart from the V57P variant, were predominantly monomeric (e.g., V57G) or in monomer/dimer equilibrium. This work might represent the first observation of domain swapping induced by high-intensity X-rays. |
BibTeX:
@article{Taube2019,
author = {Taube, Michal and Pietralik, Zuzanna and Szymanska, Aneta and Szutkowski, Kosma and Clemens, Daniel and Grubb, Anders and Kozak, Maciej},
title = {The domain swapping of human cystatin C induced by synchrotron radiation},
journal = {Sci. Rep.},
year = {2019},
volume = {9},
number = {1},
pages = {8548},
url = {https://www.nature.com/articles/s41598-019-44811-1},
doi = {10.1038/s41598-019-44811-1}
}
|
| Węglewski W, Krajewski M, Bochenek K, Denis P, Wysmołek A and Basista M (2019), "Anomalous size effect in thermal residual stresses in pressure sintered alumina-chromium composites", Mater. Sci. Eng. A., Aug, 2019. Vol. 762, pp. 138111. |
| Abstract: This paper explores an anomalous size effect in thermal residual stresses occurring in the alumina matrix of Al2O3/Cr sintered composite upon varying the particle size of the chromium reinforcement. When a coarse chromium powder (45 μm mean particle size) is used the average residual stress in the alumina phase after cooling is compressive in accordance with the classical Eshelby solution. However, in the case of a fine chromium (5 μm mean particle size) it switches to tension. This effect, detected by photoluminescence piezospectroscopy, is also confirmed by X-ray and neutron diffraction experiments. As the classical micromechanics models are incapable to capture it, a finite element model is developed with the actual composite microstructure being reconstructed from the microtomography images. It is shown by numerical simulations that the anomalous size effect is associated with the complex microstructure of the composite fabricated with the fine chromium powder. It is also pointed out that the temperature dependence of the coefficients of thermal expansion of the matrix and the reinforcement affects the residual stress levels. |
BibTeX:
@article{Weglewski2019,
author = {Węglewski, Witold and Krajewski, Marcin and Bochenek, Kamil and Denis, Piotr and Wysmołek, Andrzej and Basista, Michał},
title = {Anomalous size effect in thermal residual stresses in pressure sintered alumina-chromium composites},
journal = {Mater. Sci. Eng. A},
year = {2019},
volume = {762},
pages = {138111},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0921509319308974},
doi = {10.1016/j.msea.2019.138111}
}
|
| Wiacek U and Woźnicka U (2019), "Feasibility study of artifacts on the neutron logging curve near the boundary of layers", Acta Geophys.. Vol. 67(6), pp. 1721-1729. |
| Abstract: The neutron borehole probe equipped with a neutron source and a system of neutron detectors is commonly used to determine porosity of geological formations. Transport of neutrons through media relies on their interaction with atomic nuclei, mainly with the process of scattering and absorption. Curves recorded by detectors for a given geological layer bordered by a medium with other neutron properties form the so-called anomalies. The course of the anomaly mainly depends on neutron properties of the bordering media and also on the measurement geometry, borehole properties, etc. The paper focuses mainly on an influence of neutron properties of bordered rock media on the course of the anomaly curve, especially near the media boundaries. In some cases of bordering media, characterized by specific neutron properties, the course of anomalies can be significantly disturbed, forming specific artifacts. The paper explains that the presence of artifacts is closely related to the properties of bordered media for both fast and thermal neutrons, i.e., the slowing down length of fast neutrons and the absorption cross section of thermal neutrons. Artifacts can be the cause of misinterpretation of the neutron rock porosity probe measurement. All considerations presented in this paper are based on results obtained from MC calculations performed using MCNP5 code (MCNP Team in X-5 Monte Carlo Team, MCNP—a general Monte Carlo N-particle transport code version 5. Los Alamos National Laboratory LA-UR-03-1987, 2008). |
BibTeX:
@article{Wiacek2019,
author = {Wiacek, U. and Woźnicka, U.},
title = {Feasibility study of artifacts on the neutron logging curve near the boundary of layers},
journal = {Acta Geophys.},
year = {2019},
volume = {67},
number = {6},
pages = {1721--1729},
doi = {10.1007/s11600-019-00322-1}
}
|
| Winiarski MJ, Tran TT, Chamorro JR and McQueen TM (2019), "(CsX)Cu5O2(PO4)2 (X = Cl, Br, I): A Family of Cu2+ S = 1/2 Compounds with Capped-Kagomé Networks Composed of OCu4 Units", Inorg. Chem., Apr, 2019. Vol. 58(7), pp. 4328-4336. |
| Abstract: Three new salt inclusion compounds (CsX)Cu 5 O 2 (PO 4 ) 2 (X = Cl, Br, I), phosphate analogues of the kagomé mineral averievite, are reported. Their crystal structures are composed of trigonal networks of corner-sharing OCu 4 anion-centered tetrahedra, forming capped-kagomé planes, which can also be regarded as two-dimensional slices along the [111] direction of a pyrochlore lattice. Magnetization and heat capacity measurements reveal strong geometric frustration of this network and complex magnetic behavior. X-ray and neutron diffraction studies show that all three compounds undergo a trigonal-to-monoclinic phase transition upon cooling, with a first-order phase transition seen in CsBr and CsI analogues. Along with the previously reported (CsCl)Cu 5 O 2 (VO 4 ) 2 , these three new compounds belong to a large family of OCu 4 -based networks, which are a playground for studying frustrated quantum magnetism. |
BibTeX:
@article{Winiarski2019,
author = {Winiarski, Michal J. and Tran, Thao T. and Chamorro, Juan R. and McQueen, Tyrel M.},
title = {(Cs X)Cu 5 O 2 (PO 4 ) 2 (X = Cl, Br, I): A Family of Cu 2+ S = 1 / 2 Compounds with Capped-Kagomé Networks Composed of OCu 4 Units},
journal = {Inorg. Chem.},
year = {2019},
volume = {58},
number = {7},
pages = {4328--4336},
url = {https://pubs.acs.org/doi/10.1021/acs.inorgchem.8b03464},
doi = {10.1021/acs.inorgchem.8b03464}
}
|
| Armstrong J, Krzystyniak M, Romanelli G, Parker SF, Drużbicki K and Fernandez-Alonso F (2018), "Fractal dimension as a scaling law for nuclear quantum effects: a neutron Compton scattering study on carbon allotropes", J. Phys. Conf. Ser., Jul, 2018. Vol. 1055(1), pp. 012007. |
| Abstract: In this work, we tackle the problem of the sensitivity of neutron Compton scattering, measured through the widths of nuclear momentum distributions, to the degree of complexity and ordering of the structural motif characterising the surrounding environment felt by a particular nucleus (carbon). In doing so, we replace the usual concept of the bond strength categorised in terms of its thermodynamical or electronic properties with a novel observable inspired by the language of mathematical topology, the Hausdorff-Besicovitch fractal dimension. We derive a relatively straightforward connection between the fractal dimension of a given system under consideration and the nuclear kinetic energy. To achieve this, we modify the concept of the energy equipartition theorem for solid-state systems composed of carbon atoms where the atom-ordering topology does not follow a simple two or three-dimensional order, but rather atoms are placed along curves in space that have an intermediate dimension related to the varying amounts of information they contain. A series of results from past neutron Compton scattering studies, as well as new results on Buckminsterfullerene (C60), correlate with the topological measures of surface roughness and bending, as categorised quantitatively by the fractal dimension of the system. Namely, for the same formal chemical binding motif (sp2 C) and with decreasing system dimensionality from nearly 3 towards 1, the quantum nature of the system becomes more pronounced. The simple scaling law developed in this work allows for relatively simple assessment of the nuclear "quantumness" of a given system with potentially important ramifications in the ab initio modelling of nuclear quantum effects in condensed matter. |
BibTeX:
@article{Armstrong2018,
author = {Armstrong, J. and Krzystyniak, M. and Romanelli, G. and Parker, S F and Drużbicki, K and Fernandez-Alonso, F.},
title = {Fractal dimension as a scaling law for nuclear quantum effects: a neutron Compton scattering study on carbon allotropes},
journal = {J. Phys. Conf. Ser.},
year = {2018},
volume = {1055},
number = {1},
pages = {012007},
url = {https://iopscience.iop.org/article/10.1088/1742-6596/1055/1/012007},
doi = {10.1088/1742-6596/1055/1/012007}
}
|
| Bender P, Fock J, Frandsen C, Hansen MF, Balceris C, Ludwig F, Posth O, Wetterskog E, Bogart LK, Southern P, Szczerba W, Zeng L, Witte K, Grüttner C, Westphal F, Honecker D, González-Alonso D, Fernández Barquín L and Johansson C (2018), "Relating Magnetic Properties and High Hyperthermia Performance of Iron Oxide Nanoflowers", J. Phys. Chem. C., Feb, 2018. Vol. 122(5), pp. 3068-3077. |
| Abstract: We investigated, in depth, the interrelations among structure, magnetic properties, relaxation dynamics and magnetic hyperthermia performance of magnetic nanoflowers. The nanoflowers are about 39 nm in size, and consist of densely packed iron oxide cores. They display a remanent magnetization, which we explain by the exchange coupling between the cores, but we observe indications for internal spin disorder. By polarized small-angle neutron scattering, we unambiguously confirm that, on average, the nanoflowers are preferentially magnetized along one direction. The extracted discrete relaxation time distribution of the colloidally dispersed particles indicates the presence of three distinct relaxation contributions. We can explain the two slower processes by Brownian and classical Néel relaxation, respectively. The additionally observed very fast relaxation contributions are attributed by us to the relaxation of disordered spins within the nanoflowers. Finally, we show that the intrinsic loss power (ILP, magnetic hyperthermia performance) of the nanoflowers measured in colloidal dispersion at high frequency is comparatively large and independent of the viscosity of the surrounding medium. This concurs with our assumption that the observed relaxation in the high frequency range is primarily a result of internal spin relaxation, and possibly connected to the disordered spins within the individual nanoflowers. |
BibTeX:
@article{Bender2018,
author = {Bender, Philipp and Fock, Jeppe and Frandsen, Cathrine and Hansen, Mikkel F. and Balceris, Christoph and Ludwig, Frank and Posth, Oliver and Wetterskog, Erik and Bogart, Lara K. and Southern, Paul and Szczerba, Wojciech and Zeng, Lunjie and Witte, Kerstin and Grüttner, Cordula and Westphal, Fritz and Honecker, Dirk and González-Alonso, David and Fernández Barquín, Luis and Johansson, Christer},
title = {Relating Magnetic Properties and High Hyperthermia Performance of Iron Oxide Nanoflowers},
journal = {J. Phys. Chem. C},
year = {2018},
volume = {122},
number = {5},
pages = {3068--3077},
url = {https://pubs.acs.org/doi/10.1021/acs.jpcc.7b11255},
doi = {10.1021/acs.jpcc.7b11255}
}
|
| Bender P, Fock J, Hansen MF, Bogart LK, Southern P, Ludwig F, Wiekhorst F, Szczerba W, Zeng LJ, Heinke D, Gehrke N, Díaz MTF, González-Alonso D, Espeso JI, Fernández JR and Johansson C (2018), "Influence of clustering on the magnetic properties and hyperthermia performance of iron oxide nanoparticles", Nanotechnology., Oct, 2018. Vol. 29(42), pp. 425705. |
| Abstract: Clustering of magnetic nanoparticles can drastically change their collective magnetic properties, which in turn may influence their performance in technological or biomedical applications. Here, we investigate a commercial colloidal dispersion (FeraSpin™R), which contains dense clusters of iron oxide cores (mean size around 9 nm according to neutron diffraction) with varying cluster size (about 18-56 nm according to small angle x-ray diffraction), and its individual size fractions (FeraSpin™XS, S, M, L, XL, XXL). The magnetic properties of the colloids were characterized by isothermal magnetization, as well as frequency-dependent optomagnetic and AC susceptibility measurements. From these measurements we derive the underlying moment and relaxation frequency distributions, respectively. Analysis of the distributions shows that the clustering of the initially superparamagnetic cores leads to remanent magnetic moments within the large clusters. At frequencies below 105 rad s-1, the relaxation of the clusters is dominated by Brownian (rotation) relaxation. At higher frequencies, where Brownian relaxation is inhibited due to viscous friction, the clusters still show an appreciable magnetic relaxation due to internal moment relaxation within the clusters. As a result of the internal moment relaxation, the colloids with the large clusters (FS-L, XL, XXL) excel in magnetic hyperthermia experiments. |
BibTeX:
@article{Bender2018a,
author = {Bender, P. and Fock, J. and Hansen, M F and Bogart, L K and Southern, P. and Ludwig, F. and Wiekhorst, F. and Szczerba, W. and Zeng, L J and Heinke, D. and Gehrke, N and Díaz, M T Fernández and González-Alonso, D and Espeso, J I and Fernández, J Rodríguez and Johansson, C.},
title = {Influence of clustering on the magnetic properties and hyperthermia performance of iron oxide nanoparticles},
journal = {Nanotechnology},
year = {2018},
volume = {29},
number = {42},
pages = {425705},
url = {https://iopscience.iop.org/article/10.1088/1361-6528/aad67d},
doi = {10.1088/1361-6528/aad67d}
}
|
| Bender P, Wetterskog E, Honecker D, Fock J, Frandsen C, Moerland C, Bogart LK, Posth O, Szczerba W, Gavilán H, Costo R, Fernández-Díaz MT, González-Alonso D, Fernández Barquín L and Johansson C (2018), "Dipolar-coupled moment correlations in clusters of magnetic nanoparticles", Phys. Rev. B., Dec, 2018. Vol. 98(22), pp. 224420. |
| Abstract: Here, we resolve the nature of the moment coupling between 10-nm dimercaptosuccinic acid-coated magnetic nanoparticles. The individual iron oxide cores were composed of >95% maghemite and agglomerated to clusters. At room temperature the ensemble behaved as a superparamagnet according to Mössbauer and magnetization measurements, however, with clear signs of dipolar interactions. Analysis of temperature-dependent ac susceptibility data in the superparamagnetic regime indicates a tendency for dipolar-coupled anticorrelations of the core moments within the clusters. To resolve the directional correlations between the particle moments we performed polarized small-angle neutron scattering and determined the magnetic spin-flip cross section of the powder in low magnetic field at 300 K. We extract the underlying magnetic correlation function of the magnetization vector field by an indirect Fourier transform of the cross section. The correlation function suggests nonstochastic preferential alignment between neighboring moments despite thermal fluctuations, with anticorrelations clearly dominating for next-nearest moments. These tendencies are confirmed by Monte Carlo simulations of such core clusters. |
BibTeX:
@article{Bender2018b,
author = {Bender, P. and Wetterskog, E. and Honecker, D. and Fock, J. and Frandsen, C. and Moerland, C. and Bogart, L. K. and Posth, O. and Szczerba, W. and Gavilán, H. and Costo, R. and Fernández-Díaz, M. T. and González-Alonso, D. and Fernández Barquín, L. and Johansson, C.},
title = {Dipolar-coupled moment correlations in clusters of magnetic nanoparticles},
journal = {Phys. Rev. B},
year = {2018},
volume = {98},
number = {22},
pages = {224420},
url = {https://link.aps.org/doi/10.1103/PhysRevB.98.224420},
doi = {10.1103/PhysRevB.98.224420}
}
|
| Borowska-Centkowska A, Leszczyńska M, Krok F, Malys M, Wrobel W, Hull S and Abrahams I (2018), "Local structure and conductivity behaviour in Bi7WO13.5", J. Mater. Chem. A. Vol. 6(13), pp. 5407-5418. |
| Abstract: The structure and electrical properties of the oxide ion conductor Bi7WO13.5 have been examined as a function of temperature using neutron diffraction, differential thermal analysis and a.c. impedance spectroscopy. At room temperature, Bi7WO13.5 exhibits the type Ib tetragonally ordered fluorite structure, with tungsten distributed over two of the six cation sites. Reverse Monte Carlo (RMC) analysis of total neutron scattering data reveals a more realistic picture of the tungsten coordination environment than obtained by the average crystallographic analysis, with tungsten in predominantly tetrahedral coordination and an average bismuth coordination number of around 5. At 893 °C on heating Bi7WO13.5 undergoes a phase transition to a cubic δ-Bi2O3 type phase. The total scattering analysis of this phase reveals significant detail of the local environments of the cations. In particular, a bimodal distribution is found for Bi-O correlations, which has been used to guide the crystallographic analysis. Even in the type Ib phase Bi7WO13.5 shows relatively high conductivity in the intermediate temperature range and measurements of the oxide ion transference number confirm this to be virtually pure ionic in nature. Analysis of the oxide ion vacancy distributions shows a preference for 〈100〉 vacancy pair alignment in both phases. Evidence for a second order phase transition at around 400 °C is discussed. |
BibTeX:
@article{Borowska-Centkowska2018,
author = {Borowska-Centkowska, A. and Leszczynska, M. and Krok, F. and Malys, M. and Wrobel, W. and Hull, S. and Abrahams, I.},
title = {Local structure and conductivity behaviour in Bi7WO13.5},
journal = {J. Mater. Chem. A},
year = {2018},
volume = {6},
number = {13},
pages = {5407--5418},
url = {http://xlink.rsc.org/?DOI=C7TA09225C},
doi = {10.1039/c7ta09225c}
}
|
| Bulavin LA, Nagorna TV, Kyzyma OA, Chudoba D, Ivankov OI, Nagornyi AV and Avdeev MV (2018), "Fullerene clustering in C70/N-methyl-2-pyrrolidone/toluene liquid system", Ukr. J. Phys.. Vol. 63(2), pp. 116-120. |
| Abstract: The structural behavior of the liquid system based on a C70 in an N-methyl-2-pyrrolidone– toluene mixture has been analyzed, by using the small-angle neutron scattering method. The experimental results testify to the selective solvation in the system. The corresponding mechanisms have been discussed. |
BibTeX:
@article{Bulavin2018a,
author = {Bulavin, L. A. and Nagorna, T. V. and Kyzyma, O. A. and Chudoba, D. and Ivankov, O. I. and Nagornyi, A. V. and Avdeev, M. V.},
title = {Fullerene clustering in C70/N-methyl-2-pyrrolidone/toluene liquid system},
journal = {Ukr. J. Phys.},
year = {2018},
volume = {63},
number = {2},
pages = {116--120},
doi = {10.15407/ujpe63.2.116}
}
|
| Bulavin L, Nagorna T, Chudoba D, Kyzyma O and Ivankov O (2018), "Small-angle neutron scattering by liquid systems of fullerenes С60 and С70", Nucl. Phys. At. Energy., Sep, 2018. Vol. 19(3), pp. 252-257. |
| Abstract: Results of studies of the cluster state of fullerenes C60 and C70 in a solution of toluene with acetonitrile, performed by small-angle neutron scattering are presented. The experiment has been carried out using the small-angle scattering spectrometer YuMO, located at the IBR-2 reactor of the Joint Institute for Nuclear Research (Dubna). It has shown that a content of acetonitrile in the solution is increased, the agglomerated fraction was increasing. Sharp tendency to aggregation was observed after the certain threshold value of acetonitrile concentration was exceeded. The processes of C60 and C70 fullerenes' cluster formation were analyzed in comparison. |
BibTeX:
@article{Bulavin2018,
author = {Bulavin, L.A. and Nagorna, T.V. and Chudoba, D. and Kyzyma, O.A. and Ivankov, O.I.},
title = {Small-angle neutron scattering by liquid systems of fullerenes С60 and С70},
journal = {Nucl. Phys. At. Energy},
year = {2018},
volume = {19},
number = {3},
pages = {252--257},
url = {http://jnpae.kinr.kiev.ua/19.3/html/19.3.0252.html},
doi = {10.15407/jnpae2018.03.252}
}
|
| Burankova T, Roedern E, Maniadaki AE, Hagemann H, Rentsch D, Łodziana Z, Battaglia C, Remhof A and Embs JP (2018), "Dynamics of the Coordination Complexes in a Solid-State Mg Electrolyte", J. Phys. Chem. Lett., Nov, 2018. Vol. 9(22), pp. 6450-6455. |
| Abstract: Coordination complexes of magnesium borohydride show promising properties as solid electrolytes for magnesium ion batteries and warrant a thorough microscopic description of factors governing their mobility properties. Here, the dynamics of Mg(BH4)2-diglyme0.5 on the atomic level are investigated by means of quasielastic neutron scattering supported by density functional theory calculations and IR and NMR spectroscopy. Employing deuterium labeling, we can unambiguously separate all the hydrogen-containing electrolyte components, which facilitate Mg2+ transport, and provide a detailed analytical description of their motions on the picosecond time scale. The planar diglyme chain coordinating the central Mg atom appears to be flexible, while two dynamically different groups of [BH4]- anions undergo reorientations. The latter has important implications for the thermal stability and conductivity of Mg(BH4)2-diglyme0.5 and demonstrates that the presence of excess Mg(BH4)2 units in partially chelated Mg complexes may improve the overall performance of related solid-state electrolytes. |
BibTeX:
@article{Burankova2018,
author = {Burankova, Tatsiana and Roedern, Elsa and Maniadaki, Aristea E. and Hagemann, Hans and Rentsch, Daniel and Łodziana, Zbigniew and Battaglia, Corsin and Remhof, Arndt and Embs, Jan P.},
title = {Dynamics of the Coordination Complexes in a Solid-State Mg Electrolyte},
journal = {J. Phys. Chem. Lett.},
year = {2018},
volume = {9},
number = {22},
pages = {6450--6455},
url = {https://pubs.acs.org/doi/10.1021/acs.jpclett.8b02965},
doi = {10.1021/acs.jpclett.8b02965}
}
|
| Campbell R, Saaka Y, Shao Y, Gerelli Y, Cubitt R, Nazaruk E, Matyszewska D and Lawrence M (2018), "Structure of surfactant and phospholipid monolayers at the air/water interface modeled from neutron reflectivity data", J. Colloid Interface Sci.. Vol. 531, pp. 98-108. |
| Abstract: Specular neutron reflectometry is a powerful technique to resolve interfacial compositions and structures in soft matter. Surprisingly however, even after several decades, a universal modeling approach for the treatment of data of surfactant and phospholipid monolayers at the air/water interface has not yet been established. To address this shortcoming, first a systematic evaluation of the suitability of different models is presented. The result is a comprehensive validation of an optimum model, which is evidently much needed in the field, and which we recommend as a starting point for future data treatment. While its limitations are openly discussed, consequences of failing to take into account various key aspects are critically examined and the systematic errors quantified. On the basis of this physical framework, we go on to show for the first time that neutron reflectometry can be used to quantify directly in situ at the air/water interface the extent of acyl chain compaction of phospholipid monolayers with respect to their phase. The achieved precision of this novel quantification is ∼10%. These advances together enhance significantly the potential for exploitation in future studies data from a broad range of systems including those involving synthetic polymers, proteins, DNA, nanoparticles and drugs. |
BibTeX:
@article{Campbell2018,
author = {Campbell, R.A. and Saaka, Y. and Shao, Y. and Gerelli, Y. and Cubitt, R. and Nazaruk, E. and Matyszewska, D. and Lawrence, M.J.},
title = {Structure of surfactant and phospholipid monolayers at the air/water interface modeled from neutron reflectivity data},
journal = {J. Colloid Interface Sci.},
year = {2018},
volume = {531},
pages = {98--108},
doi = {10.1016/j.jcis.2018.07.022}
}
|
| Champagne A, Bourdarot F, Bourges P, Piekarz P, Pinek D, Gélard I, Charlier JC and Ouisse T (2018), "Phonon dispersion curves in Cr2AlC single-crystals", Mater. Res. Lett.. Vol. 6(7), pp. 378-383. |
| Abstract: Neutron inelastic scattering is used for the first time to measure phonon dispersion branches in Cr2AlC MAX phase single crystals with appreciable size. Phonon spectra are also calculated within the Density Functional Perturbation Theory (DFPT) framework and exhibit a very good match with experimental data, including high energy carbon-related optical branches. Both experiments and ab initio simulations confirm the existence of a substantial phonon gap and discard the presence of any softening mode or possible magnetic effect. (Figure Presented). Impact Statement: We synthesized Cr2AlC single-crystalline platelets with areas over 10 cm2. This breakthrough in materials synthesis was a prerequisite for measuring inelastic neutron scattering and phonon anisotropies. |
BibTeX:
@article{Champagne2018,
author = {Champagne, A. and Bourdarot, F. and Bourges, P. and Piekarz, P. and Pinek, D. and Gélard, I. and Charlier, J. C. and Ouisse, T.},
title = {Phonon dispersion curves in Cr2AlC single-crystals},
journal = {Mater. Res. Lett.},
year = {2018},
volume = {6},
number = {7},
pages = {378--383},
doi = {10.1080/21663831.2018.1463298}
}
|
| Chatterji T, Wdowik U, Jagło G, Rols S and Wagner F (2018), "Soft-phonon dynamics of the thermoelectric β-SnSe at high temperatures", Phys. Lett. Sect. A Gen. At. Solid State Phys.. Vol. 382(29), pp. 1937-1941. |
| Abstract: Results of inelastic neutron scattering experiments on SnSe single crystals at high temperatures along with theoretical studies based on the density functional theory are reported. Our experiments reveal significant softening of the transverse acoustic branch along the [0,ξ,0] direction in the low-temperature α-SnSe of Pbnm symmetry as temperature approaches Tc=807 K from below. This process is followed by a condensation of the zone-boundary Y-phonon of the high-temperature β-SnSe with Cmcm symmetry at the onset of phase transition. The employed theoretical approach supports experimental observations and demonstrates that the phase change in SnSe is mediated by an unstable zone-boundary phonon with the Y2+ irreducible representation within the Cmcm symmetry space group of the high-temperature β-SnSe. The present work provides a detailed understanding of the soft-mode dynamics in SnSe and conclusively shows that the α⇌β structural transformation in this currently topical thermoelectric material is of displacive type. |
BibTeX:
@article{Chatterji2018,
author = {Chatterji, T. and Wdowik, U.D. and Jagło, G. and Rols, S. and Wagner, F.R.},
title = {Soft-phonon dynamics of the thermoelectric β-SnSe at high temperatures},
journal = {Phys. Lett. Sect. A Gen. At. Solid State Phys.},
year = {2018},
volume = {382},
number = {29},
pages = {1937--1941},
doi = {10.1016/j.physleta.2018.05.011}
}
|
| Chrabąszczewska M, Maszota-Zieleniak M, Pietralik Z, Taube M, Rodziewicz-Motowidło S, Szymańska A, Szutkowski K, Clemens D, Grubb A and Kozak M (2018), "Cyclic trimer of human cystatin C, an amyloidogenic protein - molecular dynamics and experimental studies", J. Appl. Phys., May, 2018. Vol. 123(17), pp. 174701. |
| Abstract: Human cystatin C (HCC) is a cysteine protease inhibitor that takes a series of oligomeric forms in solution (e.g., dimers, trimers, tetramers, decamers, dodecamers, and other higher oligomers). The best-known form of cystatin C is the dimer, which arises as a result of a domain swapping mechanism. The formation of the HCC oligomeric forms, which is most likely due to this domain swapping mechanism, is associated with the aggregation of HCC into amyloid fibrils and deposits. To investigate the structure of a specific HCC oligomer, we developed a covalently stabilized trimer of HCC. An atomic model of this HCC trimer was proposed on the basis of molecular docking and molecular dynamics simulations. The most stable model of the HCC trimer obtained from the molecular dynamics simulations is characterized by a well-preserved secondary structure. The molecular size and structural parameters of the HCC trimer in solution were also confirmed by Small Angle Neutron Scattering and Nuclear Magnetic Resonance Diffusometry. |
BibTeX:
@article{Chrabaszczewska2018,
author = {Chrabaszczewska, Magdalena and Maszota-Zieleniak, Martyna and Pietralik, Zuzanna and Taube, Michał and Rodziewicz-Motowidło, Sylwia and Szymańska, Aneta and Szutkowski, Kosma and Clemens, Daniel and Grubb, Anders and Kozak, Maciej},
title = {Cyclic trimer of human cystatin C, an amyloidogenic protein - molecular dynamics and experimental studies},
journal = {J. Appl. Phys.},
year = {2018},
volume = {123},
number = {17},
pages = {174701},
url = {http://aip.scitation.org/doi/10.1063/1.5023807},
doi = {10.1063/1.5023807}
}
|
| Ciepluch K, Radulescu A, Hoffmann I, Raba A, Allgaier J, Richter D and Biehl R (2018), "Influence of PEGylation on Domain Dynamics of Phosphoglycerate Kinase: PEG Acts Like Entropic Spring for the Protein", Bioconjug. Chem.. Vol. 29(6), pp. 1950-1960. |
| Abstract: Protein-polymer conjugation is a widely used technique to develop protein therapeutics with improved pharmacokinetic properties as prolonged half-life, higher stability, water solubility, lower immunogenicity, and antigenicity. Combining biochemical methods, small angle scattering (SAXS/SANS), and neutron spin-echo spectroscopy, here we examine the impact of PEGylation (i.e., the covalent conjugation with poly(ethylene glycol) or PEG) on structure and internal domain dynamics of phosphoglycerate kinase (PGK) to elucidate the reason for reduced activity that is connected to PEGylation. PGK is a protein with a hinge motion between the two main domains that is directly related to function. We find that secondary structure and ligand access to the binding sites are not affected. The ligand induced cleft closing is unchanged. We observe an additional internal motion between covalent bonded PEG and the protein compatible with Brownian motion of PGK in a harmonic potential. Entropic interaction with the full PEG chain leads to a force constant of about 8 pN/nm independent of PEG chain length. This additional force preserves protein structure and has negligible effects on the functional domain dynamics of the protein. PEGylation seems to reduce activity just by acting as a local crowder for the ligands. The newly identified interaction mechanism might open possibilities to improve rational design of protein-polymer conjugates. |
BibTeX:
@article{Ciepluch2018,
author = {Ciepluch, K. and Radulescu, A. and Hoffmann, I. and Raba, A. and Allgaier, J. and Richter, D. and Biehl, R.},
title = {Influence of PEGylation on Domain Dynamics of Phosphoglycerate Kinase: PEG Acts Like Entropic Spring for the Protein},
journal = {Bioconjug. Chem.},
year = {2018},
volume = {29},
number = {6},
pages = {1950--1960},
doi = {10.1021/acs.bioconjchem.8b00203}
}
|
| Cieślak J, Tobola J, Berent K and Marciszko M (2018), "Phase composition of AlxFeNiCrCo high entropy alloys prepared by sintering and arc-melting methods", J. Alloys Compd., Apr, 2018. Vol. 740, pp. 264-272. |
| Abstract: AlxFeNiCrCo (0≤x≤1.5) high entropy alloys (HEA) have been investigated experimentally in systematic way in order to complete the existing results as well as to testify the alternative method of HEA sample preparation based on sintering of pure metallic powders. Structural properties have been studied by X-ray and neutron diffraction measurements, which allowed to identify the crystal structures and their contributions in HEA samples. The phase compositions were determined from electron microscopic measurements (EDX, EBSD). The amounts of observed BCC/B2 and FCC phases obtained using these complementary techniques remains in good agreement. Within two detected crystallographic structures, three phases with different stoichiometries were identified and their appearance, composition and contribution in the investigated HEA were found to be dependent on Al content. Comparing overall results obtained for sintered and melted samples, it was shown that the phase composition of AlxFeNiCrCo alloys are very similiar, but the corresponding microstructures are quite different, i.e. dendritic structure is observed for melted samples while large regular grains for sintered ones. |
BibTeX:
@article{Cieslak2018,
author = {Cieslak, J. and Tobola, J. and Berent, K. and Marciszko, M.},
title = {Phase composition of AlxFeNiCrCo high entropy alloys prepared by sintering and arc-melting methods},
journal = {J. Alloys Compd.},
year = {2018},
volume = {740},
pages = {264--272},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838817345371},
doi = {10.1016/j.jallcom.2017.12.333}
}
|
| Drużbicki K, Krzystyniak M, Hollas D, Kapil V, Slavíček P, Romanelli G and Fernandez-Alonso F (2018), "Hydrogen dynamics in solid formic acid: insights from simulations with quantum colored-noise thermostats", J. Phys. Conf. Ser., Jul, 2018. Vol. 1055(1), pp. 012003. |
| Abstract: With an increase of computational capabilities, ab initio molecular dynamics becomes the natural choice for exploring the nuclear dynamics of solids. As based on classical mechanics, the validity of this approach is, in-principle, limited to the high-T regime, whilst low-temperature simulations require inclusion of quantum effects. The methods commonly used to account for nuclear quantum effects are based on the path-integral formalism, which become, however, particularly time consuming when high accuracy methods are used for calculating forces. Recently, new efficient alternative approaches to account for quantum nature of nuclei have been proposed, using so-called quantum thermostats. In this work, we examine the simulations performed with the quantum colored-noise thermostat introduced by Ceriotti [Phys. Rev. Lett., 103:030603, 2009]. We present the tests of portable implementation of the quantum thermostat in the ABIN program, which has been extended to periodic systems through the interface to CASTEP, a leading spectroscopy-oriented plane-wave density functional theory code. The range of applicability of quantum-thermostatted molecular dynamics simulations for the interpretation of neutron scattering data was examined and compared to classical molecular dynamics and lattice-dynamics simulations, using solid formic acid case as a test bed. We find that the approach is particularly useful for the modeling of low-temperature inelastic neutron scattering spectra as well as provides some theoretical estimate for the low-limit of the mean kinetic energy. While finding the quantum-thermostat to seriously affect the dynamic properties of the title system, we illustrate to which extent the unperturbed response can be successfully recovered. |
BibTeX:
@article{Druzbicki2018,
author = {Drużbicki, K and Krzystyniak, M. and Hollas, D. and Kapil, V. and Slavíček, P. and Romanelli, G. and Fernandez-Alonso, F.},
title = {Hydrogen dynamics in solid formic acid: insights from simulations with quantum colored-noise thermostats},
journal = {J. Phys. Conf. Ser.},
year = {2018},
volume = {1055},
number = {1},
pages = {012003},
url = {https://iopscience.iop.org/article/10.1088/1742-6596/1055/1/012003},
doi = {10.1088/1742-6596/1055/1/012003}
}
|
| Ficek F, Fadeev P, Flambaum VV, Jackson Kimball DF, Kozlov MG, Stadnik YV and Budker D (2018), "Constraints on Exotic Spin-Dependent Interactions Between Matter and Antimatter from Antiprotonic Helium Spectroscopy", Phys. Rev. Lett., May, 2018. Vol. 120(18), pp. 183002. |
| Abstract: Heretofore undiscovered spin-0 or spin-1 bosons can mediate exotic spin-dependent interactions between standard model particles. Here, we carry out the first search for semileptonic spin-dependent interactions between matter and antimatter. We compare theoretical calculations and spectroscopic measurements of the hyperfine structure of antiprotonic helium to constrain exotic spin- and velocity-dependent interactions between electrons and antiprotons. |
BibTeX:
@article{Ficek2018,
author = {Ficek, Filip and Fadeev, Pavel and Flambaum, Victor V. and Jackson Kimball, Derek F. and Kozlov, Mikhail G. and Stadnik, Yevgeny V. and Budker, Dmitry},
title = {Constraints on Exotic Spin-Dependent Interactions Between Matter and Antimatter from Antiprotonic Helium Spectroscopy},
journal = {Phys. Rev. Lett.},
year = {2018},
volume = {120},
number = {18},
pages = {183002},
url = {https://link.aps.org/doi/10.1103/PhysRevLett.120.183002},
doi = {10.1103/PhysRevLett.120.183002}
}
|
| Formalik F, Fischer M, Rogacka J, Firlej L and Kuchta B (2018), "Benchmarking of GGA density functionals for modeling structures of nanoporous, rigid and flexible MOFs", J. Chem. Phys., Aug, 2018. Vol. 149(6), pp. 064110. |
| Abstract: The adequate choice of the interaction model is essential to reproduce qualitatively and estimate quantitatively the experimentally observed characteristics of materials or phenomena in computer simulations. Here we present the results of a benchmarking of density-functional theory calculations of rigid and flexible metal-organic frameworks (MOFs). The stability of these systems depends on the dispersion interactions. We compare the performance of two functionals, Perdew-Burke-Ernzerhof (PBE) and PBE designed for solids, with and without the dispersion corrections (D2 and TS), in reproducing the high-accuracy low-temperature X-ray and neutron diffraction data for both groups of MOFs. We focus our analysis on the key structural parameters: the lattice parameters, bond lengths, and angles. We show that the dispersion long range correction is essential to stabilize the structures and, in some cases, to converge the system to a geometry that is in line with the experimentally observed structure, especially for breathing MIL-53 structures or zeolitic imidazolate frameworks. We find that for all structures and all analyzed parameters, the D2-corrected PBE functional performs the best, except for bonds involving the metal ions; however, even for these bonds the difference between the experimentally observed and calculated lengths is small. Therefore, we recommend the use of the PBE-D2 functional in further numerical analyses of rigid and flexible nanoporous MOFs. |
BibTeX:
@article{Formalik2018,
author = {Formalik, Filip and Fischer, Michael and Rogacka, Justyna and Firlej, Lucyna and Kuchta, Bogdan},
title = {Benchmarking of GGA density functionals for modeling structures of nanoporous, rigid and flexible MOFs},
journal = {J. Chem. Phys.},
year = {2018},
volume = {149},
number = {6},
pages = {064110},
url = {http://aip.scitation.org/doi/10.1063/1.5030493},
doi = {10.1063/1.5030493}
}
|
| Frelek-Kozak M, Kurpaska Ł, Pawlak W, Diduszko R, Jasiński J, Chmielewski M, Milczarek J and Zoladek-Nowak J (2018), "Implementation of GIXRD analysis and nanoindentation technique to study functional properties of materials – ODS case study", J. Mol. Struct., Aug, 2018. Vol. 1166, pp. 34-39. |
| Abstract: In this work, the effect of ion implantation and Cr content on structural properties of ODS steel have been investigated. Structural properties were measured by using Grazing Incidence X-ray Diffraction (GIXRD) and Small Angle Neutron Scattering (SANS) techniques. Mechanical properties, in the function of Cr addition were measured by means of nanoindentation technique. It has been found that bands characteristic for (100), (200) or (211) crystallographic planes, upon impact of ions change their position (shift towards lower 2θ). Implementation of Small-Angle Neutron Scattering (SANS) technique has help to estimate particle characteristics in ODS specimens. Finally, mechanical results clearly show impact of Cr addition on the hardness and Young modulus of the manufactured specimens. |
BibTeX:
@article{Frelek-Kozak2018,
author = {Frelek-Kozak, M. and Kurpaska, Ł. and Pawlak, W. and Diduszko, R. and Jasiński, J. and Chmielewski, M. and Milczarek, J. and Zoladek-Nowak, J.},
title = {Implementation of GIXRD analysis and nanoindentation technique to study functional properties of materials – ODS case study},
journal = {J. Mol. Struct.},
year = {2018},
volume = {1166},
pages = {34--39},
url = {https://linkinghub.elsevier.com/retrieve/pii/S002228601830437X},
doi = {10.1016/j.molstruc.2018.04.006}
}
|
| Gadalińska E, Baczmański A, Wroński S, Wróbel M and Scheffzük C (2018), "The hardening in alloys and composites and its examination with a diffraction and self-consistent model", Fatigue Aircr. Struct.. Vol. 2018(10), pp. 31-46. |
| Abstract: The paper presents the results of diffraction stress measurement in Al/SiC composite and in 2124T6 aluminum alloy during the in situ tensile test. The main aim of the work is to observe the stress values for different stages of tensile test for the composite after applying two types of thermal treatment and for the alloy used as a matrix in this composite, to identify the type of hardening process. The experimental results were compared against the calculations results obtained from the self-consistent model developed by Baczmański [1] - [3] to gain the information about the micromechanical properties (critical resolved shear stress τcr and hardening parameter H) of the examined materials. This comparison allowed researchers to determine the role of reinforcement in the composite as well as the impact of the heat treatment on the hardening of the material. |
BibTeX:
@article{Gadalinska2018,
author = {Gadalińska, E. and Baczmański, A. and Wroński, S. and Wróbel, M. and Scheffzük, C.},
title = {The hardening in alloys and composites and its examination with a diffraction and self-consistent model},
journal = {Fatigue Aircr. Struct.},
year = {2018},
volume = {2018},
number = {10},
pages = {31--46},
doi = {10.2478/fas-2018-0003}
}
|
| Goel V, Pietrasik J, Poling-Skutvik R, Jackson A, Matyjaszewski K and Krishnamoorti R (2018), "Structure of block copolymer grafted silica nanoparticles", Polymer (Guildf).. Vol. 159, pp. 138-145. |
| Abstract: The morphology of a block copolymer of a near symmetric strongly-segregating poly(n-butyl acrylate) and poly(methyl methacrylate) tethered to a ∼15 nm silica nanoparticles is examined using a combination of microscopy techniques and small angle x-ray and neutron scattering. The copolymer components are strongly segregated and form a disordered structure that is possibly a combination of coexisting individual randomly placed core-shell structures and worm-like cylinders with 3–5 silica nanoparticles forming the core. With increasing temperature, the cylinders become shorter because of the improved thermodynamic compatibility between the two copolymer segments. |
BibTeX:
@article{Goel2018,
author = {Goel, V. and Pietrasik, J. and Poling-Skutvik, R. and Jackson, A. and Matyjaszewski, K. and Krishnamoorti, R.},
title = {Structure of block copolymer grafted silica nanoparticles},
journal = {Polymer (Guildf).},
year = {2018},
volume = {159},
pages = {138--145},
doi = {10.1016/j.polymer.2018.10.072}
}
|
| Grins J, Wardecki D, Jansson K, Carlson S, Biendicho JJ and Svensson G (2018), "A structural study of Ruddlesden–Popper phases Sr3−xYx(Fe1.25Ni0.75)O7−δ with x ≤ 0.75 by neutron powder diffraction and EXAFS/XANES spectroscopy", J. Mater. Chem. A. Vol. 6(13), pp. 5313-5323. |
| Abstract: Ruddlesden–Popper phases Sr 3−x Y x (Fe 1.25 Ni 0.75 )O 7−δ with x ≤ 0.75 have been characterised by neutron powder diffraction and EXAFS/XANES spectroscopy. |
BibTeX:
@article{Grins2018,
author = {Grins, Jekabs and Wardecki, Dariusz and Jansson, Kjell and Carlson, Stefan and Biendicho, Jordi J. and Svensson, Gunnar},
title = {A structural study of Ruddlesden–Popper phases Sr 3−x Y x (Fe 1.25 Ni 0.75 )O 7−δ with x ≤ 0.75 by neutron powder diffraction and EXAFS/XANES spectroscopy},
journal = {J. Mater. Chem. A},
year = {2018},
volume = {6},
number = {13},
pages = {5313--5323},
url = {http://xlink.rsc.org/?DOI=C7TA07113B},
doi = {10.1039/C7TA07113B}
}
|
| Hembacher J, Badrtdinov DI, Ding L, Sobczak Z, Ritter C, Mazurenko VV and Tsirlin AA (2018), "Stripe order and magnetic anisotropy in the S=1 antiferromagnet BaMoP2O8", Phys. Rev. B., Sep, 2018. Vol. 98(9), pp. 094406. |
| Abstract: Magnetic behavior of yavapaiite-type BaMoP2O8 with the spatially anisotropic triangular arrangement of the S=1Mo4+ ions is explored using thermodynamic measurements, neutron diffraction, and density-functional band-structure calculations. A broad maximum in the magnetic susceptibility around 46 K is followed by the stripe antiferromagnetic order with the propagation vector k=(12,12,12) formed below TN≃21 K. This stripe phase is triggered by a pronounced one-dimensionality of the spin lattice, where one of the in-plane couplings, J2≃4.6 meV, is much stronger than its J1≃0.4 meV counterpart, and stabilized by the weak easy-axis anisotropy. The ordered moment of 1.42(9)μB at 1.5 K is significantly lower than the spin-only moment of 2μB due to a combined effect of quantum fluctuations and spin-orbit coupling. |
BibTeX:
@article{Hembacher2018,
author = {Hembacher, Jan and Badrtdinov, Danis I. and Ding, Lei and Sobczak, Zuzanna and Ritter, Clemens and Mazurenko, Vladimir V. and Tsirlin, Alexander A.},
title = {Stripe order and magnetic anisotropy in the S=1 antiferromagnet BaMoP2 O8},
journal = {Phys. Rev. B},
year = {2018},
volume = {98},
number = {9},
pages = {094406},
url = {https://link.aps.org/doi/10.1103/PhysRevB.98.094406},
doi = {10.1103/PhysRevB.98.094406}
}
|
| Hetmańczyk J and Hetmańczyk Ł (2018), "Dynamics of H2O ligands and ReO4− anions at the phase transition in [Mn(H2O)2](ReO4)2 studied by complementary spectroscopic methods", J. Raman Spectrosc., Feb, 2018. Vol. 49(2), pp. 298-311. |
| Abstract: The vibrational and reorientational motions of H2O ligands and ReO-4 anions in high- and low-temperature phases were investigated by means of Fourier transform far- and mid-infrared and Raman light-scattering spectroscopy and neutron scattering (inelastic/quasi-elastic incoherent neutron scattering) methods. The dynamics of H2O and ReO-4 molecules in high- (I) and low-temperature (II) phases was investigated by means of band shape analysis performed for Raman and IR bands. The temperature dependencies of full width at half maximum values of the Raman bands at 874 (νas(ReO)) and 943 cm−1 (νs(ReO)) exhibit changes in their behaviour in the vicinity of transformation, suggesting that the observed phase transition is connected with a change in the reorientational dynamics of ReO-4. However, anions also perform fast (τR ≈ 10−12 to 10−13 s) stochastic reorientational motions in Phase II. The estimated mean value of activation energy for ReO-4 anions in the low-temperature phase is Ea(II) = 8.1 kJmol−1. In infrared band shape analysis it was found that H2O ligands perform fast (picosecond correlation time scale) motions in both phases with a mean value of activation energies of 7.68 kJmol−1. These reorientational motions of H2O ligands do not contribute to the phase transition mechanism. Moreover, the observed phase transition was accompanied by the splitting of some bands, suggesting a reduction in crystal structure symmetry. Quasi-elastic neutron scattering measurements furnished evidence that H2O motion in Phase I can be fairly accurately described by a simple model of 180° jumps around a twofold axis within a picosecond time scale. Additionally, infrared, Raman light-scattering spectra were calculated using the density functional theory method for the isolated equilibrium model Mn(H2O)2(ReO4)2, and qualitative agreement with the experimental data was achieved. The theoretical vibrational spectra of the title compound were interpreted by means of potential energy distributions using the VEDA 4 program. |
BibTeX:
@article{Hetmanczyk2018a,
author = {Hetmańczyk, Joanna and Hetmańczyk, Łukasz},
title = {Dynamics of H2O ligands and ReO4− anions at the phase transition in [Mn(H2O)2](ReO4)2 studied by complementary spectroscopic methods},
journal = {J. Raman Spectrosc.},
year = {2018},
volume = {49},
number = {2},
pages = {298--311},
url = {https://onlinelibrary.wiley.com/doi/10.1002/jrs.5281},
doi = {10.1002/jrs.5281}
}
|
| Hetmańczyk J and Hetmańczyk Ł (2018), "Vibrational and reorientational dynamics and thermal properties in [Mg(H2O)4](ReO4)2 supported by periodic DFT study". Jan, 2018. |
| Abstract: The polymorphism of the [Mg(H2O)4](ReO4)2 compound was investigated for the first time by us by means of differential scanning calorimetry (DSC). The measurements were performed in the temperature range of 295–130 K on cooling and heating of the sample at different rates. One reversible phase transition of the investigated compound has been found at: Tch = 285.1 K (onset on heating) and Tcc = 256.5 K (onset on cooling). The large thermal hysteresis of the phase transition temperature Tc equal to ca. 28.6 K and the heat flow anomaly sharpness suggest that the detected phase transition is a first-order one. The moderate entropy change (ΔS ≈ 4.3 J mol−1 K−1) connected with observed phase transition indicates some kind of dynamical disorder of the high temperature phase. X-ray single crystal and neutron powder diffraction results revealed that the phase transition discovered atTCc is associated with a small change of the crystal structure. Vibrational and reorientational motions of H2O ligands and ReO4− anions, in the high (I) and low (II) temperature phases, were investigated by Fourier transform far and middle-infrared and Raman light scattering spectroscopies (FT-IR and RS). The temperature dependences of the full-width at half-maximum values (FWHM) of the bands associated with: 2δ(H2O) mode (at 3236 cm−1 in IR spectra) and νas(H–O) mode (at 3463 cm−1 in Raman spectra), suggest that the observed phase transition is not associated with a change of the H2O reorientational motions. Analysis of the FWHM vs temperature of the Raman band at 345 cm−1 connected with the δ(OReO) mode, indicate that the observed phase transition is not connected with a change of the ReO4− reorientational dynamics. From the IR and RS band shape analysis it was found that H2O ligands and ReO4− anions perform fast (correlation time scale, τR ≈ 10−11–10−13 s) motions in the both phases and their reorientational motions do not contribute to the phase transition mechanism. The estimated mean value of activation energy for H2O ligands and ReO4− anions in the both phases (high and low) is: Ea(I/II) = 8.50 ± 0.37 kJmol−1 and Ea(I/II) = 6.78 ± 0.37 kJmol−1, respectively. The density functional theory plane wave calculations of the normal modes within the periodic boundary conditions (CASTEP code) were also performed in order to support band assignment. We have obtained good agreement between calculated and experimental data (IR and RS spectra). |
BibTeX:
@misc{Hetmanczyk2018,
author = {Hetmańczyk, Joanna and Hetmańczyk, Łukasz},
title = {Vibrational and reorientational dynamics and thermal properties in [Mg(H2O)4](ReO4)2 supported by periodic DFT study},
booktitle = {Vib. Spectrosc.},
year = {2018},
volume = {94},
pages = {49--60},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0924203117302606},
doi = {10.1016/j.vibspec.2017.12.002}
}
|
| Hetmańczyk J, Hetmańczyk Ł and Nitek W (2018), "Crystal structure, phase transitions and vibrations of H2O molecules in [Ca(H2O)2](ReO4)2", J. Therm. Anal. Calorim.. Vol. 131(1), pp. 479-489. |
| Abstract: One reversible phase transition at Tch = 261.2 K (upon heating) was observed for [Ca(H2O)2](ReO4)2 in the 120–300 K range. Thermal hysteresis of the phase transition temperature TC of ca. 30 K and heat flow anomaly sharpness suggest that the detected phase transition is of a first-order type. The entropy change value (ΔS ≈ 1.6 ± 0.08 J mol−1 K−1), associated with the observed phase transition (PT), indicates a moderate degree of molecular dynamical disorder. X-ray single crystal and neutron powder diffraction measurements indicated that the crystal space group (I 2/a) is the same for the high- and low-temperature phases. However, FT-IR and RS spectra show a narrowing (during sample cooling) of the bands connected with vibrations of the H2O molecules and ReO4− ions. This suggests that the anions and the ligands from the complex cation perform rapid (picosecond correlation time scale, which is characteristic of optical spectroscopy) stochastic reorientational motions in the low- and high-temperature phases. Moreover, apart from the narrowing, the splitting of some bands can be seen below the phase transition. |
BibTeX:
@article{Hetmanczyk2018b,
author = {Hetmańczyk, Joanna and Hetmańczyk, Łukasz and Nitek, Wojciech},
title = {Crystal structure, phase transitions and vibrations of H2O molecules in [Ca(H2O)2](ReO4)2},
journal = {J. Therm. Anal. Calorim.},
year = {2018},
volume = {131},
number = {1},
pages = {479--489},
doi = {10.1007/s10973-017-6494-y}
}
|
| Hetmańczyk J, Nowicka-Scheibe J, Maurin J and Pawlukojć A (2018), "Low temperature investigations of dynamic properties in L-leucine – chloranilic acid complex", Spectrochim. Acta - Part A Mol. Biomol. Spectrosc.. Vol. 200, pp. 281-289. |
| Abstract: Inelastic neutron scattering (INS) and infra-red (IR) spectroscopy methods were used for determination of dynamic structure of L-leucine – chloranilic acid complex. A theoretical dynamic pattern calculated by the density functional theory (DFT) method for periodic boundary conditions accompanied the experimental ones. Normal modes in the vibrational spectra were defined and described. The characteristic presence of the Hadži's trio enriched by numerous submaxima is observed in the wavenumber range 3200–800 cm−1. Bands assigned to CH3 torsion vibrations in the leucine cation were observed at 231 cm−1 and 258 cm−1 in the INS spectrum. Temperature-dependent far-infrared spectra in the temperature range 9 K–290 K were obtained. Vibrational bands were analyzed as a function of temperature. Activation energies for reorientational motion of CH3 and CH2 groups were determined by means of the band shape analysis performed for torsional and twisting vibrations of these groups. The estimated energy is equal to Ea = 2.7 ± 0.2 kJ/mol and Ea = 2.17 ± 0.12 kJ/mol for CH3 and CH2 groups, respectively. A phase transition at about 130 K in the L-leucine – chloranilic acid complex was observed. |
BibTeX:
@article{Hetmanczyk2018c,
author = {Hetmańczyk, J. and Nowicka-Scheibe, J. and Maurin, J.K. and Pawlukojć, A.},
title = {Low temperature investigations of dynamic properties in L-leucine – chloranilic acid complex},
journal = {Spectrochim. Acta - Part A Mol. Biomol. Spectrosc.},
year = {2018},
volume = {200},
pages = {281--289},
doi = {10.1016/j.saa.2018.03.070}
}
|
| Holdynski M, Sintyureva M, Liu X, Leszczynska M, Krok F, Hull S and Abrahams I (2018), "Structure and conductivity in the Bi4Nb1−xYxO8.5−x oxide-ion conducting system", Solid State Ionics., Dec, 2018. Vol. 328, pp. 8-16. |
| Abstract: A study of structure and oxide-ion conductivity in the Bi4Nb1−xYxO8.5−x solid solution using X-ray and neutron powder diffraction and a.c. impedance spectroscopy is presented. Slow cooled samples are typically biphasic, exhibiting a mixture of cubic/pseudo-cubic and orthorhombic or tetragonal fluorite based phases. Single phase cubic and pseudo-cubic materials can be isolated by quenching from high temperatures. The defect structure in these quenched phases has been determined by neutron diffraction and shows an oxide-ion distribution that is compositionally dependent. This distribution is correlated with the compositional variation of the low temperature activation energy for total conductivity, whereas the activation energy for high temperature conductivity decreases with increasing value of x, reflecting the reduction in dopant-vacancy interaction with increasing yttrium content, as well as a change from a tetragonally ordered type III phase for low x-value compositions to a fully disordered δ-Bi2O3 type phase at x = 0.4. Ordering phenomena are proposed to account for the appearance of a linear intermediate temperature region with high activation energy in Arrhenius plots of conductivity at x ≥ 0.4. Conductivities in the order of 10−1 S cm−1 are achieved at 700 °C in these materials. |
BibTeX:
@article{Holdynski2018,
author = {Holdynski, M. and Sintyureva, M. and Liu, X. and Leszczynska, M. and Krok, F. and Hull, S. and Abrahams, I.},
title = {Structure and conductivity in the Bi4Nb1−xYxO8.5−x oxide-ion conducting system},
journal = {Solid State Ionics},
year = {2018},
volume = {328},
pages = {8--16},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167273818305368},
doi = {10.1016/j.ssi.2018.11.003}
}
|
| Jie H, Qiu W, Gajda D, Kim J, Anvar V, Nijhuis A, Bando Y,
Yamauchi Y, Luzin V and Shahriar A. Hossain M (2018), "Evaluation
of residual stress and texture in isotope based Mg11B |
| Abstract: Magnesium diboride (MgB2) superconducting wires have demonstrated commercial potential to replace niobium-titanium (NbTi) in terms of comparable critical current density. Its higher critical temperature makes MgB2 wire suitable for liquid-helium-free operation. We recently reported boron-11 isotope-based low-activation Mg11B2 superconducting wire with decent critical current density appropriate for low-cost superconducting fusion magnets. In this study, we have mainly focused on the neutron diffraction technique to measure the residual stress in Mg11B2 superconducting wire for the first time. The residual stress state was given qualitative and quantitative interpretation in terms of micro- and macrostress generation mechanisms based on the isotropic model confirmed by neutron texture measurements. The relationship between the stress/strain state in the wire and the transport critical current density is also discussed. This investigation could pave the way to further enhancement of the critical current density of low-activation Mg11B2 superconducting wires suitable for next-generation fusion grade magnets. |
BibTeX:
@article{Jie2018,
author = {Jie, H. and Qiu, W. and Gajda, D. and Kim, J. and Anvar, V.A. and Nijhuis, A. and Bando, Y. and Yamauchi, Y. and Luzin, V. and Shahriar A. Hossain, Md.},
title = {Evaluation of residual stress and texture in isotope based Mg11B |
| Juszyńska-Gałązka E, Zając W, Saito K, Yamamura Y and Juruś N (2018), "Vibrational dynamics of glass forming: 2-phenylbutan-1-ol (BEP), 2-(trifluoromethyl)phenethyl alcohol (2TFMP) and 4-(trifluoromethyl)phenethyl alcohol (4TFMP) in their thermodynamic phases", Phase Transitions. Vol. 91(2), pp. 170-185. |
| Abstract: The complex polymorphism and vibrational dynamics of three glass-forming single-phenyl-ring alcohols (with and without fluorine atoms) have been studied by complementary methods. Glass of isotropic liquid phase and cold crystallization of metastable supercooled liquid state were detected. Temperature investigations of vibrational motions show important role of hydrogen bonds in interactions between molecules. Theoretical calculations for isolated molecule, as well as dimer- and tetramer-type aggregates of non-covalently bound molecules, allow for a good description of experimental spectra. Intermolecular interactions of molecules with ortho and para positions of CF3 group in phenyl ring have a similar influence on the spectra observed. |
BibTeX:
@article{Juszynska-Gaazka2018,
author = {Juszyńska-Gałazka, E. and Zajac, W. and Saito, K. and Yamamura, Y. and Juruś, N.},
title = {Vibrational dynamics of glass forming: 2-phenylbutan-1-ol (BEP), 2-(trifluoromethyl)phenethyl alcohol (2TFMP) and 4-(trifluoromethyl)phenethyl alcohol (4TFMP) in their thermodynamic phases},
journal = {Phase Transitions},
year = {2018},
volume = {91},
number = {2},
pages = {170--185},
doi = {10.1080/01411594.2017.1393813}
}
|
| Keshavarz S, Kontos S, Wardecki D, Kvashnin YO, Pereiro M, Panda SK, Sanyal B, Eriksson O, Grins J, Svensson G, Gunnarsson K and Svedlindh P (2018), "Magnetic properties of Ruddlesden-Popper phases Sr3-x Yx(Fe1.25 Ni0.75) O7-δ: A combined experimental and theoretical investigation", Phys. Rev. Mater., Apr, 2018. Vol. 2(4), pp. 044005. |
| Abstract: We present a comprehensive study of the magnetic properties of Sr3-xYx(Fe1.25Ni0.75)O7-δ(0≤x≤0.75). Experimentally, the magnetic properties are investigated using superconducting quantum interference device (SQUID) magnetometry and neutron powder diffraction (NPD). This is complemented by a theoretical study based on density functional theory as well as the Heisenberg exchange parameters. Experimental results show an increase in the Néel temperature (TN) with an increase of Y concentrations and O occupancy. The NPD data reveal that all samples are antiferromagnetically ordered at low temperatures, which has been confirmed by our theoretical simulations for the selected samples. Our first-principles calculations suggest that the three-dimensional magnetic order is stabilized due to finite interlayer exchange couplings. The latter give rise to finite interlayer spin-spin correlations, which disappear above TN. |
BibTeX:
@article{Keshavarz2018,
author = {Keshavarz, Samara and Kontos, Sofia and Wardecki, Dariusz and Kvashnin, Yaroslav O. and Pereiro, Manuel and Panda, Swarup K. and Sanyal, Biplab and Eriksson, Olle and Grins, Jekabs and Svensson, Gunnar and Gunnarsson, Klas and Svedlindh, Peter},
title = {Magnetic properties of Ruddlesden-Popper phases Sr3-x Yx(Fe1.25 Ni0.75) O7-δ: A combined experimental and theoretical investigation},
journal = {Phys. Rev. Mater.},
year = {2018},
volume = {2},
number = {4},
pages = {044005},
url = {https://link.aps.org/doi/10.1103/PhysRevMaterials.2.044005},
doi = {10.1103/PhysRevMaterials.2.044005}
}
|
| Krzystyniak M, Romanelli G, Druzbicki K, Tolchenov R, Gigg M, Hewer B and Fernandez-Alonso F (2018), "Model selection in neutron Compton scattering - A Bayesian approach with physical constraints", In J. Phys. Conf. Ser.. Vol. 1055(1), pp. 012012. |
| Abstract: This work analyses the performance of the maximum-likelihood estimation approach in fitting Gram-Charlier expansion curves to nuclear momentum distributions with non-negativity constraints. The presented approach guarantees that the most likely model selected to describe the recorded data is also a physically meaningful one, i.e., corresponds to a non-negative probability distribution function. For the case of the most popular momentum distribution model, containing the information about the variance and excess kurtosis of the distribution, we derive a simple and easy to implement non-negativity criterion. We test the performance of the newly developed approach by applying it to interpret proton momentum distribution obtained from neutron Compton scattering from solid phosphoric acid, a system in which nuclear quantum tunnelling was proposed in the limit of low temperature. From a methodological point of view, this work provides a screening tool in the search for systems exhibiting the so-called 'non-trivial nuclear quantum effects'. |
BibTeX:
@inproceedings{Krzystyniak2018,
author = {Krzystyniak, M. and Romanelli, G. and Druzbicki, K. and Tolchenov, R. and Gigg, M. and Hewer, B. and Fernandez-Alonso, F.},
title = {Model selection in neutron Compton scattering - A Bayesian approach with physical constraints},
booktitle = {J. Phys. Conf. Ser.},
year = {2018},
volume = {1055},
number = {1},
pages = {012012},
doi = {10.1088/1742-6596/1055/1/012012}
}
|
| Kuna R, Fabrèges X, Petit S, Minikayev R, Korczak J, Szczerbakow A and Szuszkiewicz W (2018), "Low-temperature neutron diffraction in the (Pb,Cd)Te solid solution containing 2.2% of CD", Acta Phys. Pol. A. Vol. 134(4), pp. 944-946. |
| Abstract: The (Pb,Cd)Te solid solution forms a metastable single crystals for a solution containing more than 1% of CdTe due to its very low solubility in PbTe. A possible presence of a phase transitions at low temperatures (like, e.g., that occurring in the (Pb,Ge)Te solid solution starting from 1% of Ge) which could influence the physical properties of (Pb,Cd)Te system was never checked. In order to verify this possibility the neutron diffraction studies were performed in the temperature range from 21 K to 39 K in the single crystal of (Pb,Cd)Te solid solution with 2.2% of CdTe grown by self-selecting vapour growth method and characterized by powder X-ray diffraction. The (Pb,Cd)Te sample was measured using the four-circle diffractometer installed at a hot neutron source (λ = 0.83 Å). The possible transition does not take place to the lowest investigated temperature and the FWHM of Bragg peaks remains fixed in all temperature range under studies. |
BibTeX:
@article{Kuna2018,
author = {Kuna, R. and Fabrèges, X. and Petit, S. and Minikayev, R. and Korczak, J. and Szczerbakow, A. and Szuszkiewicz, W.},
title = {Low-temperature neutron diffraction in the (Pb,Cd)Te solid solution containing 2.2% of CD},
journal = {Acta Phys. Pol. A},
year = {2018},
volume = {134},
number = {4},
pages = {944--946},
doi = {10.12693/APhysPolA.134.944}
}
|
| Maj J, Basista M, Węglewski W, Bochenek K, Strojny-Nędza A, Naplocha K, Panzner T, Tatarková M and Fiori F (2018), "Effect of microstructure on mechanical properties and residual stresses in interpenetrating aluminum-alumina composites fabricated by squeeze casting", Mater. Sci. Eng. A. Vol. 715, pp. 154-162. |
| Abstract: Aluminum-alumina composites with interpenetrating network structure are interesting structural materials due to their high resistance to elevated temperature and frictional wear, good heat conductivity, enhanced mechanical strength and fracture toughness. In this paper aluminum-alumina bulk composites and FGMs are manufactured by pressure infiltration of porous alumina preforms with molten aluminum alloy (EN AC-44200). Influence of the interpenetrating microstructure on the macroscopic bending strength, fracture toughness, hardness and heat conduction is examined. Special focus is on processing-induced thermal residual stresses in aluminum-alumina composites due to their potentially detrimental effects on material performance in structural elements under in-service conditions. The residual stresses are measured experimentally in the ceramic phase by neutron diffraction and simulated numerically using a micro-CT based Finite Element model, which takes into account the actual interpenetrating microstructure of the composite. The model predictions for two different volume fractions of alumina agree fairly well with the neutron diffraction measurements. |
BibTeX:
@article{Maj2018,
author = {Maj, J. and Basista, M. and Węglewski, W. and Bochenek, K. and Strojny-Nędza, A. and Naplocha, K. and Panzner, T. and Tatarková, M. and Fiori, F.},
title = {Effect of microstructure on mechanical properties and residual stresses in interpenetrating aluminum-alumina composites fabricated by squeeze casting},
journal = {Mater. Sci. Eng. A},
year = {2018},
volume = {715},
pages = {154--162},
doi = {10.1016/j.msea.2017.12.091}
}
|
| Mori A, Mamiya H, Ohnuma M, Ilavsky J, Ohishi K, Woźniak J, Olszyna A, Watanabe N, Suzuki J, Kitazawa H, Kitazawa H and Lewandowska M (2018), "Manufacturing and characterization of Ni-free N-containing ODS austenitic alloy", J. Nucl. Mater.. Vol. 501, pp. 72-81. |
| Abstract: Ni-free N-containing oxide dispersion strengthened (ODS) austenitic alloys were manufactured by mechanical alloying (MA) followed by spark plasma sintering (SPS). The phase evolutions during milling under a nitrogen atmosphere and after sintering were studied by X-ray diffraction (XRD). Transmission electron microcopy (TEM) and alloy contrast variation analysis (ACV), including small-angle neutron scattering (SANS) and ultra-small-angle X-ray scattering (USAXS), revealed the existence of nanoparticles with a diameter of 3–51 nm for the samples sintered at 950 °C. Sintering at 1000 °C for 5 and 15 min caused slight growth and a significant coarsening of the nanoparticles, up to 70 nm and 128 nm, respectively. The ACV analysis indicated the existence of two populations of Y2O3, 𝜖-martensite and MnO. The dispersive X-ray spectrometry (EDS) confirmed two kinds of nanoparticles, Y2O3 and MnO. The material was characterized by superior micro-hardness, of above 500 HV0.1. |
BibTeX:
@article{Mori2018,
author = {Mori, A. and Mamiya, H. and Ohnuma, M. and Ilavsky, J. and Ohishi, K. and Woźniak, J. and Olszyna, A. and Watanabe, N. and Suzuki, J. and Kitazawa, H. and Kitazawa, H. and Lewandowska, M.},
title = {Manufacturing and characterization of Ni-free N-containing ODS austenitic alloy},
journal = {J. Nucl. Mater.},
year = {2018},
volume = {501},
pages = {72--81},
doi = {10.1016/j.jnucmat.2018.01.025}
}
|
| Naberezhnov A, Vanina P, Sysoeva A, Ciźman A, Rysiakiewicz-Pasek E and Hoser A (2018), "Effect of Restricted Geometry on the Structure and Phase Transitions in Potassium Nitrate Nanoparticles", Phys. Solid State. Vol. 60(3), pp. 442-446. |
| Abstract: The effect of restricted geometry and thermal prehistory of sample preparation on phase transitions in nanocomposites on base of porous glasses with average pore diameters 7 and 46 nm filled by potassium nitrate have been studied by X-rays and neutron diffraction. The nanoparticle sizes have been determined and phase diagrams (on cooling) for these nanoparticles have been described. It is shown that there is a critical nanoparticle size in the interval from 30 till 20 nm, at which in nanocomposite the ferroelectric phase is realized only regardless of preparation method. |
BibTeX:
@article{Naberezhnov2018,
author = {Naberezhnov, A.A. and Vanina, P.Y. and Sysoeva, A.A. and Ciźman, A. and Rysiakiewicz-Pasek, E. and Hoser, A.},
title = {Effect of Restricted Geometry on the Structure and Phase Transitions in Potassium Nitrate Nanoparticles},
journal = {Phys. Solid State},
year = {2018},
volume = {60},
number = {3},
pages = {442--446},
doi = {10.1134/S1063783418030204}
}
|
| Olejniczak A, Szafrański M and Katrusiak A (2018), "Pressure-Temperature Phase Diagrams and Transition Mechanisms of Hybrid Organic-Inorganic NHtextperiodcenteredtextperiodcenteredtextperiodcenteredN Bonded Ferroelectrics", Cryst. Growth Des.. Vol. 18(11), pp. 6488-6496. |
| Abstract: The ferroelectric-paraelectric transitions of 1,4-diazabicyclo[2.2.2]octane (dabco) tetrafluoroborate (dabcoHBF4) and perchlorate (dabcoHClO4), between their phases II (orthorhombic space group Pm21n) and I (tetragonal space group P4/nmm) proceed at TC = 377 and 378 K, respectively. On approaching phase I the anions are strongly shifted by about 0.8 Å and become disordered, but the protons remain ordered in the NH+textperiodcenteredtextperiodcenteredtextperiodcenteredN bonds. In phase I, the disordered protons and anions approximate the tetragonal space group P4/mmm with a twice-smaller unit cell, but due to small displacements of the dabcoH+ cations the crystal acquires the symmetry of tetragonal space group P4/nmm, with the unit cell compatible with that of phase II. The structures have been determined by single-crystal X-ray and neutron diffraction. DabcoHBF4 has been also investigated at high pressure and its new phases have been revealed. The high pressure phases IV of dabcoHBF4 and III of dabcoHClO4 are isostructural. High-pressure in situ crystallizations in a diamond-anvil cell yield also hydrate dabcoHBF4textperiodcenteredH2O of an unprecedented structure, where the crystallization water molecules are OHtextperiodcenteredtextperiodcenteredtextperiodcenteredO bonded into zigzag chains parallel to the NH+textperiodcenteredtextperiodcenteredtextperiodcenteredN bonded cations. |
BibTeX:
@article{Olejniczak2018,
author = {Olejniczak, A. and Szafrański, M. and Katrusiak, A.},
title = {Pressure-Temperature Phase Diagrams and Transition Mechanisms of Hybrid Organic-Inorganic NHtextperiodcenteredtextperiodcenteredtextperiodcenteredN Bonded Ferroelectrics},
journal = {Cryst. Growth Des.},
year = {2018},
volume = {18},
number = {11},
pages = {6488--6496},
doi = {10.1021/acs.cgd.8b00581}
}
|
| Pajzderska A, Drużbicki K, Gonzalez M, Jenczyk J, Mielcarek J and Wasicki J (2018), "Diversity of methyl group dynamics in felodipine: a DFT supported NMR and QENS study", CrystEngComm. Vol. 20(45), pp. 7371-7385. |
| Abstract: Molecular and vibrational dynamics in a widely used calcium channel blocker, felodipine form I (FLD), have been thoroughly explored by combining periodic density functional theory (plane-wave DFT) with solid-state nuclear magnetic resonance (NMR), high-resolution quasielastic neutron scattering (QENS) and inelastic neutron scattering (INS) experiments. The crystallographic structure of FLD is found to be strongly stabilized by a manifold of stacking interactions, highly immobilizing the molecular frameworks and bringing on considerably anharmonic lattice dynamics, further probed by combining ab initio molecular dynamics simulations with phonon calculations. The performance of modern van der Waals corrections to density functional theory has been critically examined and compared with the results of the INS and NMR experiments. The experimental results uncover rich internal reorientational dynamics, spanning almost four orders of magnitude on the time-scale. On the basis of the combined experimental and computational protocols, the relaxation processes have been probed in a broad range of temperatures and frequencies and characterized in terms of their type, time scale and the associated activation barriers. The internal molecular mobility of FLD can be associated with the reorientational dynamics of four methyl groups, accompanied by high-amplitude librations of an alkyl ester side chain. Noticeably, internal molecular reorientations dominate above ca. 100 K, whereas motions of considerable quantum nature are clearly observed at low temperatures. In such a way, a consistent picture of the molecular dynamics in the most stable form of FLD is provided, facilitating our understanding of the relationships between the crystal environment, molecular mobility and conformational flexibility in this important pharmaceutical solid. |
BibTeX:
@article{Pajzderska2018,
author = {Pajzderska, A. and Drużbicki, K. and Gonzalez, M.A. and Jenczyk, J. and Mielcarek, J. and Wasicki, J.},
title = {Diversity of methyl group dynamics in felodipine: a DFT supported NMR and QENS study},
journal = {CrystEngComm},
year = {2018},
volume = {20},
number = {45},
pages = {7371--7385},
doi = {10.1039/C8CE01605D}
}
|
| Pavlosiuk O, Fabreges X, Gukasov A, Meven M, Kaczorowski D and Wiśniewski P (2018), "Magnetic structures of REPdBi half-Heusler bismuthides (RE = Gd, Tb, Dy, Ho, Er)", Phys. B Condens. Matter. Vol. 536, pp. 56-59. |
| Abstract: We present results of neutron diffraction on single crystals of several equiatomic ternary compounds of rare-earth elements with palladium and bismuth, crystallizing with cubic MgAgAs-type structure (half-Heusler phases). Band structure calculations showed that many members of that family possess electronic band inversion, which may lead to occurrence of topological insulator or topological semimetal. But even for the compounds without intrinsic band inversion another way of topologically non-trivial state realization, through a specific antiferromagnetic order, has been theoretically proposed. Our results show that the antiferromagnetic structures of all studied bismuthides are characterized by the propagation vector, allowing for antiferromagnetic topological insulator state. Therefore, the antiferromagnetic representatives of half-Heusler family are excellent candidates for extended investigations of coexistence of superconductivity, magnetic order and non-trivial topology of electronic states. |
BibTeX:
@article{Pavlosiuk2018,
author = {Pavlosiuk, O. and Fabreges, X. and Gukasov, A. and Meven, M. and Kaczorowski, D. and Wiśniewski, P.},
title = {Magnetic structures of REPdBi half-Heusler bismuthides (RE = Gd, Tb, Dy, Ho, Er)},
journal = {Phys. B Condens. Matter},
year = {2018},
volume = {536},
pages = {56--59},
doi = {10.1016/j.physb.2017.10.062}
}
|
| Pavlosiuk O, Kleinert M, Wiśniewski P and Kaczorowski D (2018), "Antiferromagnetic order in the half-Heusler phase TbPdBi", Acta Phys. Pol. A. Vol. 133(3), pp. 498-500. |
| Abstract: Single crystals of TbPdBi, a representative of the group of half-Heusler bismuthides, were studied by means of magnetic susceptibility, heat capacity, electrical resistivity, magnetostriction and thermal expansion measurements. The compound was characterized as an antiferromagnet with the Néel temperature TN ≈ 5.3 K. Neutron diffraction experiment confirmed the antiferromagnetic ordering and yielded the propagation vector k = (1/2, 1/2, 1/2). Remarkably, this k vector is in accord with the recently developed theory of antiferromagnetic topological insulators. |
BibTeX:
@article{Pavlosiuk2018a,
author = {Pavlosiuk, O. and Kleinert, M. and Wiśniewski, P. and Kaczorowski, D.},
title = {Antiferromagnetic order in the half-Heusler phase TbPdBi},
journal = {Acta Phys. Pol. A},
year = {2018},
volume = {133},
number = {3},
pages = {498--500},
doi = {10.12693/APhysPolA.133.498}
}
|
| Penc B, Hoser A, Baran S, Duraj R, Marzec M, Jaworska-Gołab T, Szytuła A, Dyakonov V, Nedelko N, Sivachenko A, Bażela W and Szymczak H (2018), "Influence of Ti atoms on the magnetic order in quaternary NiMnGe:Ti compounds", Phase Transitions. Vol. 91(11), pp. 1107-1121. |
| Abstract: The NiMn0.95Ti0.05MnGe and Ni1–xTixMnGe (x = 0.05, 0.15 and 0.25) compounds have been studied by X-ray (at room temperature), neutron diffraction (2–360 K), DSC (130–390 K) and magnetic studies (2–350 K). The compounds with a low Ti concentration exhibit an orthorhombic crystal structure of NiTiSi-type (space group Pnma), whereas those with a large Ti content exhibit a hexagonal Ni2In-type structure (space group P63/mmc). The compounds with x = 0.05 are antiferromagnets with the helicoidal magnetic structure. The samples with the hexagonal crystal structure have a noncollinear magnetic structure with antiferro- along a-axis and ferro- along c-axis components. The obtained magnetic entropy change (Formula presented.) has the maximum value equal to 6.2 J/kgK at T = 200 K and H = 90 kOe for Ni0.85Ti0.15MnGe. For compounds with x = 0.05, 0.15 and 0.25, the magnetic (P, T) phase diagrams, under hydrostatic pressure up to 12 kbar, were determined. |
BibTeX:
@article{Penc2018,
author = {Penc, B. and Hoser, A. and Baran, S. and Duraj, R. and Marzec, M. and Jaworska-Gołab, T. and Szytuła, A. and Dyakonov, V. and Nedelko, N. and Sivachenko, A. and Bażela, W. and Szymczak, H.},
title = {Influence of Ti atoms on the magnetic order in quaternary NiMnGe:Ti compounds},
journal = {Phase Transitions},
year = {2018},
volume = {91},
number = {11},
pages = {1107--1121},
doi = {10.1080/01411594.2018.1502884}
}
|
| Penc B, Hoser A, Baran S and Szytuła A (2018), "Helicoidal ordering in NiMn1-xCrxGe for x = 0, 0.04, 0.11 and 0.18", Phase Transitions., Feb, 2018. Vol. 91(2), pp. 118-127. |
| Abstract: The work reports the results of neutron diffraction measurements of NiMn1-xCrxGe for x = 0, 0.04, 0.11 and 0.18 with λ equal to 4.567 Å. The experiment was performed in the temperature range 2–380 K. Partial substitution of Cr for Mn does not change the orthorhombic crystal structure. For the samples with x = 0, 0.04 and 0.11, a helicoidal ordering with the propagation vector k = (ka, 0, 0) is observed in broad temperature range up to the Nèel temperature. The values of the ka component decrease with increasing Cr content. For x = 0, a change from double to simple helix is observed near 250 K with increasing temperature, while in the Cr doped compounds only simple helix was detected. For x = 0.18, the helicoidal ordering changes to ferromagnetic one at 160 K. |
BibTeX:
@article{Penc2018a,
author = {Penc, Bogusław and Hoser, Andreas and Baran, Stanisław and Szytuła, Andrzej},
title = {Helicoidal ordering in NiMn1-xCrxGe for x = 0, 0.04, 0.11 and 0.18},
journal = {Phase Transitions},
year = {2018},
volume = {91},
number = {2},
pages = {118--127},
url = {https://www.tandfonline.com/doi/full/10.1080/01411594.2017.1411488},
doi = {10.1080/01411594.2017.1411488}
}
|
| Peti W, Page R, Boura E and Różycki B (2018), "Structures of dynamic protein complexes: Hybrid techniques to study MAP kinase complexes and the ESCRT system", In Methods Mol. Biol.. Vol. 1688, pp. 375-389. |
| Abstract: The integration of complementary molecular methods (including X-ray crystallography, NMR spectroscopy, small angle X-ray/neutron scattering, and computational techniques) is frequently required to obtain a comprehensive understanding of dynamic macromolecular complexes. In particular, these techniques are critical for studying intrinsically disordered protein regions (IDRs) or intrinsically disordered proteins (IDPs) that are part of large protein:protein complexes. Here, we explain how to prepare IDP samples suitable for study using NMR spectroscopy, and describe a novel SAXS modeling method (ensemble refinement of SAXS; EROS) that integrates the results from complementary methods, including crystal structures and NMR chemical shift perturbations, among others, to accurately model SAXS data and describe ensemble structures of dynamic macromolecular complexes. |
BibTeX:
@book{Peti2018,
author = {Peti, W. and Page, R. and Boura, E. and Różycki, B.},
title = {Structures of dynamic protein complexes: Hybrid techniques to study MAP kinase complexes and the ESCRT system},
booktitle = {Methods Mol. Biol.},
year = {2018},
volume = {1688},
pages = {375--389},
doi = {10.1007/978-1-4939-7386-6_17}
}
|
| Przenioslo R, Fabrykiewicz P and Sosnowska I (2018), "Crystal symmetry aspects of materials with magnetic spin reorientation", Acta Crystallogr. Sect. A Found. Adv.. Vol. 74(6), pp. 705-708. |
| Abstract: The symmetry of materials which undergo a continuous spin reorientation has been analysed. It is shown that continuous spin reorientation is possible only in materials with triclinic or monoclinic crystal structure symmetry, i.e. other symmetries – orthorhombic, tetragonal, trigonal, hexagonal and cubic – are forbidden. |
BibTeX:
@article{Przenioslo2018,
author = {Przenioslo, R. and Fabrykiewicz, P. and Sosnowska, I.},
title = {Crystal symmetry aspects of materials with magnetic spin reorientation},
journal = {Acta Crystallogr. Sect. A Found. Adv.},
year = {2018},
volume = {74},
number = {6},
pages = {705--708},
doi = {10.1107/S2053273318012822}
}
|
| Przeniosło R, Fabrykiewicz P, Sosnowska I, Wardecki D, Sławiński W, Playford H, Hempelmann R and Bukowski M (2018), "Crystallite size effect on the monoclinic deformation of the bcc crystal structure of chromium", Phys. B Condens. Matter. Vol. 530, pp. 183-190. |
| Abstract: The modulated spin density wave magnetic orderings observed in chromium suggests that the crystal structure of chromium cannot be described by the cubic space group Im3¯m. Our experimental studies of polycrystalline and nanocrystalline chromium by synchrotron radiation (SR) and neutron powder diffraction show a hkl-dependent Bragg peak broadening which can be interpreted by the low-symmetry monoclinic space group P21/n instead of the high symmetry cubic space group Im3¯m. The monoclinic angle is βm = 90.05(1)° and 90.29(1)° for polycrystalline Cr and nanocrystalline Cr, respectively. The relative monoclinic distortion observed in chromium is 5 times larger than those reported for several oxides: BiFeO3, α-Fe2O3, Cr2O3 and calcite. The symmetry of the magnetic transverse spin density wave (TSDW) and the longitudinal spin density wave (LSDW) observed in Cr are described by using the superspace groups P21/n(0β0)00 and P21′/n′(0β0)00, respectively. These superspace groups describe both the magnetic modulations and the atomic position modulations reported in the literature. The monoclinic symmetry of chromium is a robust effect which is observed in the paramagnetic as well as in the TSDW and LSDW phases. |
BibTeX:
@article{Przenioso2018,
author = {Przeniosło, R. and Fabrykiewicz, P. and Sosnowska, I. and Wardecki, D. and Sławiński, W.A. and Playford, H.Y. and Hempelmann, R. and Bukowski, M.},
title = {Crystallite size effect on the monoclinic deformation of the bcc crystal structure of chromium},
journal = {Phys. B Condens. Matter},
year = {2018},
volume = {530},
pages = {183--190},
doi = {10.1016/j.physb.2017.10.086}
}
|
| Radlinski A and Mastalerz M (2018), "Neutron scattering study of vitrinite: Insights into sub-micrometer inclusions in North American Carboniferous coals of bituminous rank", Int. J. Coal Geol.. Vol. 186, pp. 145-154. |
| Abstract: Results of SANS and USANS measurements performed on a series of six vitrinite samples having vitrinite reflectance (Ro) values ranging from 0.55% (high volatile bituminous rank) to 1.28% (medium volatile bituminous rank) were analyzed. Experimental data were acquired for two sample forms: platelets cut parallel to the bedding and pellets made up of randomly oriented, nearly-monodisperse particles. Numerical analysis indicates the presence of sub-micron sized inclusions embedded in the organic matrix. For the lowest-rank vitrinites, the dominating inclusions are monodisperse are ∼ 7–12 nm in diameter, and have concentrations of the order of 1017 cm− 3. Their shape is anisotropic, with the surface-to-volume ratio about three times larger than for a solid sphere. The higher-rank vitrinites contain much larger monodisperse inclusions having diameters of ∼ 50 nm, concentrations of ∼ 1014 cm− 3, large surface-to-volume ratios, and fuzzy interfaces with the organic matrix. Inclusions of a similar size and concentration are also present in the lowest-rank sample, but are much less frequent than the small inclusions. We provisionally interpret those objects as inclusions of mineral matter, most likely associated with original plant material. The internal specific surface area (SSA) calculated for the small mineral matter inclusions is ∼ 100 m2/cm3 and for the large inclusions ∼ 2 m2/cm3. |
BibTeX:
@article{Radlinski2018,
author = {Radlinski, A.P. and Mastalerz, M.},
title = {Neutron scattering study of vitrinite: Insights into sub-micrometer inclusions in North American Carboniferous coals of bituminous rank},
journal = {Int. J. Coal Geol.},
year = {2018},
volume = {186},
pages = {145--154},
doi = {10.1016/j.coal.2017.10.012}
}
|
| Rajewska A, Islamov AK and Bakeeva RF (2018), "Aggregation study in mixture surfactant system TX-100+SDS in heavy water solutions by SANS method", J. Phys. Conf. Ser., Mar, 2018. Vol. 994(1), pp. 012015. |
| Abstract: The mixing of amphiphiles in water may lead to the formation of mixed micelles which often present new properties with respect to the pure component solutions [1,2]. The mixture system of classic surfactants SDS (sodium dodecyl sulfate)+TX-100(p-(1,1,3,3- tetramethyl) poly(oxyethylene) (anionic + non-ionic) in heavy water solutions was investigated at temperatures 30°, 50°, 70°C for compositions 1:1, 2:1, 3:1 by the small-angle neutron scattering(SANS) method on spectrometer ('YuMO') at the IBR-2 pulsed neutron source at FLNP, JINR in Dubna (Russia). Measurements have covered Q range from 8x10-3 to 0.4 Å-1. From the measured dependence of the scattered intensity on the scattering angle, we derived the size, shape of micelles, aggregation number at various compositions and temperatures. The size of mixed micelle is a weak function of the mixing ratio between the two components. |
BibTeX:
@article{Rajewska2018,
author = {Rajewska, A. and Islamov, A. Kh. and Bakeeva, R. F.},
title = {Aggregation study in mixture surfactant system TX-100+SDS in heavy water solutions by SANS method},
journal = {J. Phys. Conf. Ser.},
year = {2018},
volume = {994},
number = {1},
pages = {012015},
url = {https://iopscience.iop.org/article/10.1088/1742-6596/994/1/012015},
doi = {10.1088/1742-6596/994/1/012015}
}
|
| Rećko K, Klekotka U, Kalska-Szostko B, Soloviov D, Satuła D and Waliszewski J (2018), "Properties of Ga-doped magnetite nanoparticles", Acta Phys. Pol. A. Vol. 134(5), pp. 998-1002. |
| Abstract: This paper reports our progress toward developing the best methods to prepare Ga-doped magnetite nanoparticles. Results of X-ray powder diffraction, small angle neutron scattering and the Mössbauer spectroscopy measurements of core-shell Ga0.2Fe2.8O4/ Fe3O4 and Fe3O4/Ga0.2Fe2.8O4 nanoparticles are presented. They all were found to crystallize in the cubic structure. The diffraction data confirmed high sensitivity of the phase homogeneity depending on the preparation method. The volume of the unit cell has been proved to be independent of the gallium content. X-ray measurements disclosed that Ga atoms occupy preferentially (A) sites, while (B) sites are entirely occupied by Fe cations. The Mössbauer results are fully consistent with diffraction ones when Ga0.2Fe2.8O4 is a core of core-shell systems. The small angle neutron scattering was performed in order to test the shape and size of particles. |
BibTeX:
@article{Recko2018,
author = {Rećko, K. and Klekotka, U. and Kalska-Szostko, B. and Soloviov, D. and Satuła, D. and Waliszewski, J.},
title = {Properties of Ga-doped magnetite nanoparticles},
journal = {Acta Phys. Pol. A},
year = {2018},
volume = {134},
number = {5},
pages = {998--1002},
doi = {10.12693/APhysPolA.134.998}
}
|
| Rećko K, Waliszewski J, Klekotka U, Soloviov D, Ostapczuk G, Satuła D, Biernacka M, Balasoiu M, Basa A, Kalska-Szostko B, Kalska-Szostko B and Szymański K (2018), "Phase composition and magnetism of sol–gel synthesized Ga–Fe–O nanograins", Phase Transitions. Vol. 91(2), pp. 128-139. |
| Abstract: We have succeeded in synthesizing orthorhombic Ga(1−x)Fe(1+x)O3 (−0.05 (Formula presented.) x (Formula presented.) 0.5), hexagonal GayFe(2−y)O3 (0 (Formula presented.) y (Formula presented.) 1.8) and cubic Ga(1+z)Fe(2−z)O4 (−0.1 (Formula presented.) z (Formula presented.) 0.8) nanograins of gallium ferrites using conventional precursors and an organic environment of Pechini scenario under atmospheric-pressure conditions (SG method). Phase composition and homogeneity were analyzed using X-ray diffraction. Small angle neutron scattering disclosed ellipsoidal particle shapes of gallium iron oxides (GFO) crystallizing in orthorhombic (o-GFO) and hexagonal (h-GFO) symmetry and parallelepiped shapes of Ga(1+y)Fe(2−y)O4 (c-GFO) grains. Despite local agglomeration among the magnetic grains, the scanning electron microscopy and transmission electron microscopy images point to faced-elliptical shapes. The Mössbauer spectroscopy with magnetization measurements was carried out in the temperature range of 5–295 K. The analysis of gallium ferrites magnetism demonstrates that iron atoms locate with various probabilities in crystallographic positions and the spontaneous magnetization preserves up to room temperature (RT). |
BibTeX:
@article{Recko2018a,
author = {Rećko, K. and Waliszewski, J. and Klekotka, U. and Soloviov, D. and Ostapczuk, G. and Satuła, D. and Biernacka, M. and Balasoiu, M. and Basa, A. and Kalska-Szostko, B. and Kalska-Szostko, B. and Szymański, K.},
title = {Phase composition and magnetism of sol–gel synthesized Ga–Fe–O nanograins},
journal = {Phase Transitions},
year = {2018},
volume = {91},
number = {2},
pages = {128--139},
doi = {10.1080/01411594.2017.1409351}
}
|
| Rok M, Bator G, Medycki W, Zamponi M, Balčiūnas S, Šimėnas M and Banys J (2018), "Reorientational dynamics of organic cations in perovskite-like coordination polymers", Dalt. Trans.. Vol. 47(48), pp. 17329-17341. |
| Abstract: Here we report the dynamics of organic cations as guest molecules in a perovskite host-framework. The molecular motion of CH3NH3+ (MAFe), (CH3)2NH2+ (DMAFe) and (CH3)3NH+ (TrMAFe) in the cage formed by KFe(CN)63− units was studied using a combination of experimental methods: (i) thermal analysis, (ii) dielectric and electric studies, (iii) optical observations, (iv) EPR and 1H NMR spectroscopy and (v) quasielastic neutron scattering (QENS). In the case of MAFe and TrMAFe, the thermal analysis reveals one solid-to-solid phase transition (PT) and two PTs for the DMAFe crystal. A markedly temperature-dependent dielectric constant indicates the tunable and switchable properties of the complexes. Also, their semiconducting properties are confirmed by a dc conductivity measurement. The broadband dielectric relaxation is analyzed for the TrMAFe sample in the frequency range of 100 Hz-1 GHz. QENS shows that we deal rather with the localized motion of the cation than a diffusive one. Three models, which concern the simultaneous rotation of the CH3 and/or NH3 group, π-flips and free rotations of the organic cation, are used to fit the elastic incoherent structure factor. The 1H NMR spin-lattice relaxation time for all compounds under study, as well as the second moments, has been measured in a wide temperature range. In all studied samples, the temperature dependence of the second moment of the proton NMR line indicated the gradual evolution of the molecular movements from the rigid state up to a highly disordered one. |
BibTeX:
@article{Rok2018,
author = {Rok, M. and Bator, G. and Medycki, W. and Zamponi, M. and Balčiūnas, S. and Šimėnas, M. and Banys, J.},
title = {Reorientational dynamics of organic cations in perovskite-like coordination polymers},
journal = {Dalt. Trans.},
year = {2018},
volume = {47},
number = {48},
pages = {17329--17341},
doi = {10.1039/C8DT03372B}
}
|
| Rok M, Bator G, Sawka-Dobrowolska W, Durlak P, Moskwa M, Medycki W, Sobczyk L and Zamponi M (2018), "Crystal structural analysis of methyl-substituted pyrazines with anilic acids: A combined diffraction, inelastic neutron scattering, 1H-NMR study and theoretical approach", CrystEngComm. Vol. 20(14), pp. 2016-2028. |
| Abstract: The crystal and molecular structures of (1) 2-methylpyrazine (2MP) with 2,5-dichloro-3,6-dihydroxy-p-quinone (chloranilic acid, CLA), (2) 2-methylpyrazine (2MP) with 2,5-dibromo-3,6-dihydroxy-p-quinone (bromanilic acid, BRA), (3) 2,3,5-trimethylpyrazine (TrMP) with 2,5-dichloro-3,6-dihydroxy-p-quinone (chloranilic acid, CLA), and (4) 2,3,5-trimethylpyrazine (TrMP) with 2,5-dibromo-3,6-dihydroxy-p-quinone (bromanilic acid, BRA) were analyzed in terms of the number of independent methyl groups in their crystal structure. The inelastic neutron back-scattering spectra at low temperature (4-40 K) were discussed in terms of methyl group tunnelling. The INS spectra were compared with the temperature dependence of the 1H-NMR spin-lattice relaxation time, particularly at low temperatures, where CH3 tunnelling is postulated. The infrared and Raman spectra at room temperature were recorded for all complexes under investigation. Furthermore, the vibrational spectra were discussed in terms of the structure of molecules and their interactions. The structural phase transition of the TrMPtextperiodcenteredCLA complex at 171/175 K (cooling/heating) was characterized by DSC and single-crystal X-ray diffraction. Full-geometry optimization was carried out in the solid state in order to obtain the minimum structures and bonding properties. The results are in very good agreement with the experimental data. The infrared spectrum in the harmonic approximation was calculated and a comparative vibrational analysis was performed. CRYSTAL09 vibrational results appear to be in good agreement with the experimental results. |
BibTeX:
@article{Rok2018a,
author = {Rok, M. and Bator, G. and Sawka-Dobrowolska, W. and Durlak, P. and Moskwa, M. and Medycki, W. and Sobczyk, L. and Zamponi, M.},
title = {Crystal structural analysis of methyl-substituted pyrazines with anilic acids: A combined diffraction, inelastic neutron scattering, 1H-NMR study and theoretical approach},
journal = {CrystEngComm},
year = {2018},
volume = {20},
number = {14},
pages = {2016--2028},
doi = {10.1039/c8ce00040a}
}
|
| Ruppert L and Radlinski A (2018), "In honor of Dr. Yuri B. Melnichenko: Application of neutron scattering (SANS and USANS) to research on fossil fuel energy sources", Int. J. Coal Geol.. Vol. 189, pp. 68-69. |
BibTeX:
@article{Ruppert2018,
author = {Ruppert, L.F. and Radlinski, A.P.},
title = {In honor of Dr. Yuri B. Melnichenko: Application of neutron scattering (SANS and USANS) to research on fossil fuel energy sources},
journal = {Int. J. Coal Geol.},
year = {2018},
volume = {189},
pages = {68--69},
doi = {10.1016/j.coal.2018.02.021}
}
|
| Rzepka P, Bacsik Z, Smeets S, Hansen TC, Hedin N and Wardecki D (2018), "Site-Specific Adsorption of CO2 in Zeolite NaK-A", J. Phys. Chem. C., Nov, 2018. Vol. 122(47), pp. 27005-27015. |
| Abstract: Zeolite |Na12|-A is a commercial adsorbent, and its CO2-over-N2(CH4) selectivity can be further enhanced kinetically by replacing Na+ in the 8-ring windows that control gas diffusion with large cations. In this study, samples of zeolite |Na12-xKx|-A with x = 0.0, 0.8, 2.0, and 3.0 were prepared, and the positions of adsorbed CO2 molecules were determined using in situ neutron powder diffraction through profile refinement. Adsorbed CO2 molecules were located at three different sites within the large α-cavities in the zeolite structure, revealing the interaction between the adsorbed CO2 and the host framework. The number of CO2 molecules at each site depends on CO2 pressure and follows site-specific CO2 isotherms described with a Langmuir model. Most of the CO2 molecules in zeolite |Na12-xKx|-A bridge two cations at neighboring 8-ring sites. These are relatively weakly physisorbed, and therefore, most of the working capacity of CO2 adsorption is related to this site. The CO2 molecules at the second most populated site are coordinated to a cation in the 8-ring plane. Some of them seemed to form chemical bonds with the O atoms of the framework as carbonate-like species and acted as chemisorption. The remaining minor fraction of CO2 is directly attracted by Na+ at the 6-rings. The different positioning of physisorbed CO2 and the presence of chemisorbed CO2 was confirmed by in situ infrared spectroscopy. |
BibTeX:
@article{Rzepka2018,
author = {Rzepka, Przemyslaw and Bacsik, Zoltán and Smeets, Stef and Hansen, Thomas C. and Hedin, Niklas and Wardecki, Dariusz},
title = {Site-Specific Adsorption of CO2 in Zeolite NaK-A},
journal = {J. Phys. Chem. C},
year = {2018},
volume = {122},
number = {47},
pages = {27005--27015},
url = {https://pubs.acs.org/doi/10.1021/acs.jpcc.8b09405},
doi = {10.1021/acs.jpcc.8b09405}
}
|
| Salamatin DA, Sidorov VA, Kichanov SE, Velichkov A, Salamatin AV, Fomicheva LN, Kozlenko DP, Nikolaev AV, Menzel D, Budzynski M and Tsvyashchenko AV (2018), "Coexistence of charge density wave and incommensurate antiferromagnetism in the cubic phase of DyGe2.85 synthesised under high pressure", J. Alloys Compd.. Vol. 755, pp. 10-14. |
| Abstract: A novel metastable phase of DyGe2.85 synthesised in the AuCu3-structure under high pressure, has been studied by means of the magnetic susceptibility and electrical resistivity measurements (under the pressure P≤3.1 GPa), neutron powder diffraction and time-differential γ-γ perturbed angular correlations (TDPAC) using 111Cd nuclear probes. Two distinct phase transitions have been found in this compound as the temperature is lowered. We assign the first transition occurring at the temperature TCDW=80 K with charge density wave formation and the second transition at TN≈18 K with an antiferromagnetic spiral ordering of Dy magnetic moments, and discuss a close relationship between them. |
BibTeX:
@article{Salamatin2018,
author = {Salamatin, D. A. and Sidorov, V. A. and Kichanov, S. E. and Velichkov, A. and Salamatin, A. V. and Fomicheva, L. N. and Kozlenko, D. P. and Nikolaev, A. V. and Menzel, D. and Budzynski, M. and Tsvyashchenko, A. V.},
title = {Coexistence of charge density wave and incommensurate antiferromagnetism in the cubic phase of DyGe2.85 synthesised under high pressure},
journal = {J. Alloys Compd.},
year = {2018},
volume = {755},
pages = {10--14},
doi = {10.1016/j.jallcom.2018.04.319}
}
|
| Szklarz P, Jakubas R, Piecha-Bisiorek A, Bator G, Chański M, Medycki W and Wuttke J (2018), "Organic-inorganic hybrid crystals, (2,4,6-CH3PyH)3Sb2Cl9 and (2,4,6-CH3PyH)3Bi2Cl9. Crystal structure characterization and tunneling of CH3 groups studied by 1H NMR and neutron spectroscopy", Polyhedron., Jan, 2018. Vol. 139, pp. 249-256. |
| Abstract: The crystal structures of (2,4,6-CH3PyH)3Sb2Cl9 (TMPCA) and (2,4,6-CH3PyH)3Bi2Cl9 (TMPCB) (Py – pyridine) have been determined at 100 K by the single crystal X-ray diffraction method. TMPCA and TMPCB crystallize in the monoclinic C2/c and triclinic P1 polar space group, respectively. In both cases the asymmetric part is comprised of three nonequivalent 2,4,6-trimethylpyridinium cations and a discrete M2Cl93− anion. The Bi2Cl93− moiety forms a face-sharing bi-octahedron, whereas in a case of Sb2Cl93− we deal with two pyramids connected by a corner. The inelastic neutron scattering spectra (INS) were recorded for TMPCA at low temperatures (4–50 K). Two peaks on each side of the central elastic line have been observed at ca. 4.8 and 2.9 μeV, the high energy peak exhibits an excitation energy value equal to ca. 6 meV. For TMPCA and TMPCB the 1H NMR spin–lattice relaxation times, T1, have been measured in the temperature region 15–410 K. The flattening of the T1 (spin–lattice) vs. reciprocal temperature, 1/T, dependence between 30 K and 15 K indicates the incoherent tunneling effect of the methyl group being treated as the quantum rotor. The conclusions drawn from the 1H NMR results as regards to the tunneling of the CH3 groups in the pyridinium cations are consistent with the tunneling peaks observed in the INS spectra. |
BibTeX:
@article{Szklarz2018,
author = {Szklarz, P. and Jakubas, R. and Piecha-Bisiorek, A. and Bator, G. and Chański, M. and Medycki, W. and Wuttke, J.},
title = {Organic-inorganic hybrid crystals, (2,4,6-CH3PyH)3Sb2Cl9 and (2,4,6-CH3PyH)3Bi2Cl9. Crystal structure characterization and tunneling of CH3 groups studied by 1H NMR and neutron spectroscopy},
journal = {Polyhedron},
year = {2018},
volume = {139},
pages = {249--256},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0277538717306927},
doi = {10.1016/j.poly.2017.10.030}
}
|
| Szlęzak J, Kelly J, Ingram A, Shpotyuk Y, Adamiak S, Dziedzic A, Cebulski J and Golovchak R (2018), "Role of Bi and Ga additives in the physical properties and structure of GeSe4-GeTe4 glasses", Mater. Charact., Aug, 2018. Vol. 142, pp. 50-58. |
| Abstract: The influence of Bi on a structure and physical properties of mixed Ga-containing Ge-Se and Ge-Te glasses is studied. Partially ordered nanoscale regions observed with high-resolution transmission electron microscopy are compared with first sharp diffraction peak parameters determined through neutron and X-ray scattering studies. Nanoindentation measurements show quite small deviations in nanohardness (H) and Young's modulus (E) values for glasses with 1 and 5 at.% of Bi, while two regions with different mechanical properties are observed for sample with 10 at.% of Bi. Increase in Bi concentration from 1 at.% to 5 at.% leads to a complete opacity of ∼2 mm thick glass in a whole IR range of spectrum, while no drastic difference between these two samples is observed by SEM, TEM, XRD and neutron scattering methods. Short-range order features and possible electron defect structure are evaluated using EXAFS/XANES and PAL spectroscopies, respectively. |
BibTeX:
@article{Szlezak2018,
author = {Szlęzak, J. and Kelly, J. and Ingram, A. and Shpotyuk, Ya and Adamiak, S. and Dziedzic, A. and Cebulski, J. and Golovchak, R.},
title = {Role of Bi and Ga additives in the physical properties and structure of GeSe4-GeTe4 glasses},
journal = {Mater. Charact.},
year = {2018},
volume = {142},
pages = {50--58},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1044580318307502},
doi = {10.1016/j.matchar.2018.05.030}
}
|
| Tagliente G, Aberle O, Alcayne V, Andrzejewski J, Audouin L, Babiano-Suarez V, Bacak M, Barbagallo M, Bécares V, Benedikt T, Wright T and Žugec P (2018), "Nuclear Astrophysics at n_TOF facility, CERN", In Proc. 15th Int. Conf. Nucl. React. Mech. NRM 2018. , pp. 251-257. |
| Abstract: CERN's neutron time-of-flight facility n_TOF has produced a considerable amount of experimental data since it has become fully operational with the start of its scientific measurement programme in 2001. The innovative features of the facility, in the two experimental areas, (flight paths 20 m and 185 m), allow for an accurate determination of the neutron cross section for radioactive samples or for isotopes with small neutron capture cross section, of interest for Nuclear Astrophysics. An outline of the experimental nuclear astrophysical data activities at n_TOF will be presented. |
BibTeX:
@inproceedings{Tagliente2018,
author = {Tagliente, G. and Aberle, O. and Alcayne, V. and Andrzejewski, J. and Audouin, L. and Babiano-Suarez, V. and Bacak, M. and Barbagallo, M. and Bécares, V. and Benedikt, Th. and Wright, T. and Žugec, P.},
title = {Nuclear Astrophysics at n_TOF facility, CERN},
booktitle = {Proc. 15th Int. Conf. Nucl. React. Mech. NRM 2018},
year = {2018},
pages = {251--257}
}
|
| Tchoń D, Makal A, Gutmann M and Woźniak K (2018), "Doxycycline hydrate and doxycycline hydrochloride dihydrate - Crystal structure and charge density analysis", Zeitschrift fur Krist. - Cryst. Mater.. Vol. 233(9-10), pp. 649-661. |
| Abstract: High-resolution low-temperature X-ray diffraction experiments for doxycycline monohydrate and hydrochloride dihydrate have been performed. Translation-Libration-Screw (TLS) analysis for both crystal forms as well as the data from neutron diffraction experiment for hydrochloride combined with the Hansen-Coppens formalism resulted in precise charge density distribution models for both the zwitterionic monohydrate and a protonated hydrochloride crystal forms. Their detailed topological analysis suggested that the electron structure of doxycycline's amide moiety undergoes significant changes during protonation due to formation of a very strong resonance-assisted hydrogen bond. A notably increased participation of amide nitrogen atom and hydrogen-accepting oxygen atom in the resonance upon doxycycline protonation was observed. A comparison of TLS- and neutron data-derived hydrogen parameters confirmed the experimental neutron data to be vital for proper description of intra- and inter-molecular interactions in this compound. Finally, calculated lattice and interaction energies quantified repulsive Dox-Dox interactions in the protonated crystal form of the antibiotic, relating with a good solubility of doxycycline hydrochloride relative to its hydrate. |
BibTeX:
@article{Tchon2018,
author = {Tchoń, D. and Makal, A. and Gutmann, M. and Woźniak, K.},
title = {Doxycycline hydrate and doxycycline hydrochloride dihydrate - Crystal structure and charge density analysis},
journal = {Zeitschrift fur Krist. - Cryst. Mater.},
year = {2018},
volume = {233},
number = {9-10},
pages = {649--661},
doi = {10.1515/zkri-2018-2058}
}
|
| Yaremchenko AA, Patrakeev MV, Naumovich EN and Khalyavin DD (2018), "The: P (O2)- T stability domain of cubic perovskite Ba0.5Sr0.5Co0.8Fe0.2O3-δ", Phys. Chem. Chem. Phys.. Vol. 20(6), pp. 4442-4454. |
| Abstract: Cubic perovskite-type Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) is one of the mixed ionic-electronic conductors with the highest oxygen permeability known to date. It serves as a parent material for the development of functional derivatives for electrochemical applications including oxygen separation membranes, solid electrolyte cell electrodes and electrocatalysts for the oxygen evolution reaction. The present study is focused on the determination of the precise stability boundaries of cubic perovskite BSCF employing a coulometric titration technique in combination with thermogravimetric analysis, X-ray and neutron diffraction, and molecular dynamics simulations. Both the low-p(O2) and high-p(O2) stability boundaries at 700-950 °C were found to correspond to a fixed value of oxygen content in the perovskite lattice of 3 - δ = ∼2.13 and ∼2.515, respectively. The stability limits in this temperature range are expressed by the following equations: high-p(O2) boundary: logp(O2) (atm) (±0.1) = -10150/T (K) + 8.055; low-p(O2) boundary: logp(O2) (atm) (±0.03) = -20750/T (K) + 4.681. The p(O2)-T phase diagram of the BSCF system under oxidizing conditions is addressed in a wider temperature range and is shown to include a region of precipitation of a "low-temperature" phase occurring at 400-500 °C. The fraction of the low-temperature precipitate, which co-exists with the cubic perovskite phase and is stable up to 790-820 °C, increases upon increasing p(O2) in the range 0.21-1.0 atm. |
BibTeX:
@article{Yaremchenko2018,
author = {Yaremchenko, Aleksey A. and Patrakeev, Mikhail V. and Naumovich, Eugene N. and Khalyavin, Dmitry D.},
title = {The: P (O2)- T stability domain of cubic perovskite Ba0.5Sr0.5Co0.8Fe0.2O3- δ},
journal = {Phys. Chem. Chem. Phys.},
year = {2018},
volume = {20},
number = {6},
pages = {4442--4454},
url = {http://xlink.rsc.org/?DOI=C7CP07307K},
doi = {10.1039/c7cp07307k}
}
|
| Babilas R, Łukowiec D and Temleitner L (2017), "Atomic structure of Mg-based metallic glass investigated with neutron diffraction, reverse Monte Carlo modeling and electron microscopy", Beilstein J. Nanotechnol., May, 2017. Vol. 8(1), pp. 1174-1182. |
| Abstract: The structure of a multicomponent metallic glass, Mg 65 Cu 20 Y 10 Ni 5 , was investigated by the combined methods of neutron diffraction (ND), reverse Monte Carlo modeling (RMC) and high-resolution transmission electron microscopy (HRTEM). The RMC method, based on the results of ND measurements, was used to develop a realistic structure model of a quaternary alloy in a glassy state. The calculated model consists of a random packing structure of atoms in which some ordered regions can be indicated. The amorphous structure was also described by peak values of partial pair correlation functions and coordination numbers, which illustrated some types of cluster packing. The N = 9 clusters correspond to the tri-capped trigonal prisms, which are one of Bernal's canonical clusters, and atomic clusters with N = 6 and N = 12 are suitable for octahedral and icosahedral atomic configurations. The nanocrystalline character of the alloy after annealing was also studied by HRTEM. The selected HRTEM images of the nanocrystalline regions were also processed by inverse Fourier transform analysis. The high-angle annular dark-field (HAADF) technique was used to determine phase separation in the studied glass after heat treatment. The HAADF mode allows for the observation of randomly distributed, dark contrast regions of about 4–6 nm. The interplanar spacing identified for the orthorhombic Mg 2 Cu crystalline phase is similar to the value of the first coordination shell radius from the short-range order. |
BibTeX:
@article{Babilas2017,
author = {Babilas, Rafał and Łukowiec, Dariusz and Temleitner, Laszlo},
title = {Atomic structure of Mg-based metallic glass investigated with neutron diffraction, reverse Monte Carlo modeling and electron microscopy},
journal = {Beilstein J. Nanotechnol.},
year = {2017},
volume = {8},
number = {1},
pages = {1174--1182},
url = {https://www.beilstein-journals.org/bjnano/articles/8/119},
doi = {10.3762/bjnano.8.119}
}
|
| Baran S, Szytuła A and Hoser A (2017), "Collinear antiferromagnetic structure in R2Ni2In (R = Er, Tm)", J. Alloys Compd., Mar, 2017. Vol. 696, pp. 1278-1281. |
| Abstract: R2Ni2In (R = Er, Tm) which crystalizes in the orthorhombic structure of the Mn2AlB2-type was investigated by powder neutron diffractometry. At low temperatures the rare earth magnetic moments form an antiferromagnetic structure related to the propagation vector k→=[12,0,12]. The magnetic moments are parallel to the b-axis and equal to 7.71(7) μBand 5.76(4) μBfor Er and Tm, respectively. In order to verify validity of obtained magnetic structure model a symmetry analysis was performed. |
BibTeX:
@article{Baran2017,
author = {Baran, S. and Szytuła, A. and Hoser, A.},
title = {Collinear antiferromagnetic structure in R2Ni2In (R = Er, Tm)},
journal = {J. Alloys Compd.},
year = {2017},
volume = {696},
pages = {1278--1281},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838816339792},
doi = {10.1016/j.jallcom.2016.12.072}
}
|
| Bażela W, Dul M, Szytuła A and Dyakonov V (2017), "Grain Size Effect on Crystal Microstructure of the Nanoparticle TbMnO3 Manganite", In Springer Proc. Phys.. Vol. 195, pp. 445-456. |
| Abstract: Investigated in this paper, the poly- and nanocrystalline TbMnO3 samples crystallize in the orthorhombically distorted perovskite structure (space group Pnma, No. 62). The Tb atoms and O1 atoms are in 4(c) site, Mn atoms in 4(b) site, and O2 atoms in 8(d) site. All the samples exhibit antiferromagnetic ordering below different Néel temperatures: 7 K (Tb) and 41 K (Mn). The Tb3+ and Mn3+ moments form similar sine-modulated magnetic structures described by the propagation vector k = (kx,0,0) with the different values of the kx component. On the basis of neutron diffraction data, the Mn-O bond lengths, Mn-O-Mn bond angles, Jahn-Teller distortion parameter (JT), MnO6 octahedron distortion parameter (delta), and unit cell volume distortion (D) for the poly- and nanocrystalline TbMnO3 samples are determined. Also we have discussed the influence of the internal structural parameters (Mn-O bond lengths and Mn-O-Mn bond angles) on the magnetic interactions in Mn sublattice for the polycrystalline and nanopowder TbMnO3 samples. |
BibTeX:
@incollection{Bazela2017,
author = {Bażela, Wiesława and Dul, Marcin and Szytuła, Andrzej and Dyakonov, Volodymyr},
title = {Grain Size Effect on Crystal Microstructure of the Nanoparticle TbMnO3 Manganite},
booktitle = {Springer Proc. Phys.},
year = {2017},
volume = {195},
pages = {445--456},
url = {http://link.springer.com/10.1007/978-3-319-56422-7_33},
doi = {10.1007/978-3-319-56422-7_33}
}
|
| Bender P, Bogart LK, Posth O, Szczerba W, Rogers SE, Castro A, Nilsson L, Zeng LJ, Sugunan A, Sommertune J, Fornara A, González-Alonso D, Barquín LF and Johansson C (2017), "Structural and magnetic properties of multi-core nanoparticles analysed using a generalised numerical inversion method", Sci. Rep., Apr, 2017. Vol. 7(1), pp. 45990. |
| Abstract: The structural and magnetic properties of magnetic multi-core particles were determined by numerical inversion of small angle scattering and isothermal magnetisation data. The investigated particles consist of iron oxide nanoparticle cores (9 nm) embedded in poly(styrene) spheres (160 nm). A thorough physical characterisation of the particles included transmission electron microscopy, X-ray diffraction and asymmetrical flow field-flow fractionation. Their structure was ultimately disclosed by an indirect Fourier transform of static light scattering, small angle X-ray scattering and small angle neutron scattering data of the colloidal dispersion. The extracted pair distance distribution functions clearly indicated that the cores were mostly accumulated in the outer surface layers of the poly(styrene) spheres. To investigate the magnetic properties, the isothermal magnetisation curves of the multi-core particles (immobilised and dispersed in water) were analysed. The study stands out by applying the same numerical approach to extract the apparent moment distributions of the particles as for the indirect Fourier transform. It could be shown that the main peak of the apparent moment distributions correlated to the expected intrinsic moment distribution of the cores. Additional peaks were observed which signaled deviations of the isothermal magnetisation behavior from the non-interacting case, indicating weak dipolar interactions. |
BibTeX:
@article{Bender2017,
author = {Bender, P. and Bogart, L. K. and Posth, O. and Szczerba, W. and Rogers, S. E. and Castro, A. and Nilsson, L. and Zeng, L. J. and Sugunan, A. and Sommertune, J. and Fornara, A. and González-Alonso, D. and Barquín, L. Fernández and Johansson, C.},
title = {Structural and magnetic properties of multi-core nanoparticles analysed using a generalised numerical inversion method},
journal = {Sci. Rep.},
year = {2017},
volume = {7},
number = {1},
pages = {45990},
url = {https://www.nature.com/articles/srep45990},
doi = {10.1038/srep45990}
}
|
| Bilski P, Druz̀bicki K, Jenczyk J, Mielcarek J and Wa̧sicki J (2017), "Molecular and Vibrational Dynamics in the Cholesterol-Lowering Agent Lovastatin: Solid-State NMR, Inelastic Neutron Scattering, and Periodic DFT Study", J. Phys. Chem. B. Vol. 121(13), pp. 2776-2787. |
| Abstract: Molecular and vibrational dynamics of a widely used cholesterol-lowering agent, lovastatin, have been studied by combining nuclear magnetic resonance relaxation experiments (1H NMR) with inelastic neutron scattering (INS) and periodic density functional theory modeling (plane-wave DFT). According to a complementary experimental study, lovastatin shows no phase transitions down to cryogenic conditions, while a progressive, stepwise activation of several molecular motions is observed below room temperature. The molecular packing and intermolecular forces were analyzed theoretically, supported by a 13C NMR study and further correlated with observed molecular dynamics. The NMR relaxation experiments combined with theoretical calculations disclose that molecular dynamics in solid lovastatin is related to methyl group motions and conformational disorder in the methylbutanoate fragment. This is precisely assigned and analyzed quantitatively from both experimental and theoretical perspectives. The neutron vibrational spectroscopy further corroborates that the methyl rotors have a classical nature. In addition to the intramolecular reorientations, the vibrational dynamics was analyzed with an emphasis on the low-wavenumber range. For the first time, the terahertz response of lovastatin was studied by confronting neutron and optical techniques and clearly illustrating their complementarity. The consistent picture of the molecular dynamics is provided, which may support further considerations on alternative drug formulations and the amorphization tendency in this important lipid-lowering drug. |
BibTeX:
@article{Bilski2017,
author = {Bilski, P. and Druz̀bicki, K. and Jenczyk, J. and Mielcarek, J. and Wa̧sicki, J.},
title = {Molecular and Vibrational Dynamics in the Cholesterol-Lowering Agent Lovastatin: Solid-State NMR, Inelastic Neutron Scattering, and Periodic DFT Study},
journal = {J. Phys. Chem. B},
year = {2017},
volume = {121},
number = {13},
pages = {2776--2787},
doi = {10.1021/acs.jpcb.7b01090}
}
|
| Borowska-Centkowska A, Leszczynska M, Wrobel W, Malys M, Krynski M, Hull S, Krok F and Abrahams I (2017), "Structure and conductivity in tungsten doped δ-Bi3YO6", Solid State Ionics., Oct, 2017. Vol. 308, pp. 61-67. |
| Abstract: Solid solution formation in the system Bi3Y1 − xWxO6 + 3x/2 has been studied using a combination of X-ray and neutron powder diffraction and a.c. impedance spectroscopy. Compositions in the solid solution adopt the δ-Bi2O3 type structure, with single phases evident from x = 0.00 to x = 0.20. Evidence for dopant clustering is presented and discussed. Models for the defect structure derived from diffraction studies are presented. Tungsten is proposed to adopt a tetrahedral coordination geometry, with a distorted octahedral geometry adopted by yttrium. Calculated coordination numbers for bismuth of around five are consistent with stereochemical activity of the Bi 6s2 lone pairs of electrons. Despite a significant lowering of the nominal vacancy concentration with respect to δ-Bi3YO6, as well as enhanced vacancy trapping by W6+, tungsten doping is found to have very little influence on the total conductivity of δ-Bi3YO6. This is attributed to the compensating effect of enhanced oxide ion mobility caused by lattice expansion. |
BibTeX:
@article{Borowska-Centkowska2017,
author = {Borowska-Centkowska, A. and Leszczynska, M. and Wrobel, W. and Malys, M. and Krynski, M. and Hull, S. and Krok, F. and Abrahams, I.},
title = {Structure and conductivity in tungsten doped δ-Bi3YO6},
journal = {Solid State Ionics},
year = {2017},
volume = {308},
pages = {61--67},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167273817302230},
doi = {10.1016/j.ssi.2017.06.001}
}
|
| Burankova T, Duchêne L, Łodziana Z, Frick B, Yan Y, Kühnel R-S, Hagemann H, Remhof A and Embs JP (2017), "Reorientational Hydrogen Dynamics in Complex Hydrides with Enhanced Li+ Conduction", J. Phys. Chem. C., Aug, 2017. Vol. 121(33), pp. 17693-17702. |
| Abstract: Lithium amide-borohydrides Li[BH4]1-x[NH2]x possess liquid-like Li superionic conductivity at nearly ambient temperature. The fast Li+ diffusion facilitated by the localized motions of the anions is proposed to occur through a network of vacant tetrahedral sites, acting as conduction channels. To study the reorientational dynamics of the anions, we have performed quasielastic neutron scattering experiments on samples with different compositions (x = 2/3, 0.722, 0.737, 3/4) over a broad temperature and time range. To unambiguously disentangle the contributions of the two species, [BH4]- and [NH2]-, we took advantage of deuterium labeling and could clearly demonstrate that the quasielastic broadening is mainly determined by the [BH4]- reorientations. With the help of a newly developed model, supported by ab initio molecular dynamics calculations, we have identified three relaxation components, which account for generally anisotropic C3-rotations of the [BH4]- tetrahedra including jumps by a small angle from the equilibrium position. |
BibTeX:
@article{Burankova2017,
author = {Burankova, Tatsiana and Duchêne, Léo and Łodziana, Zbigniew and Frick, Bernhard and Yan, Yigang and Kühnel, Ruben-Simon and Hagemann, Hans and Remhof, Arndt and Embs, Jan P.},
title = {Reorientational Hydrogen Dynamics in Complex Hydrides with Enhanced Li + Conduction},
journal = {J. Phys. Chem. C},
year = {2017},
volume = {121},
number = {33},
pages = {17693--17702},
url = {https://pubs.acs.org/doi/10.1021/acs.jpcc.7b05651},
doi = {10.1021/acs.jpcc.7b05651}
}
|
| Busch M, Kityk AV, Piecek W, Hofmann T, Wallacher D, Całus S, Kula P, Steinhart M, Eich M and Huber P (2017), "A ferroelectric liquid crystal confined in cylindrical nanopores: reversible smectic layer buckling, enhanced light rotation and extremely fast electro-optically active Goldstone excitations", Nanoscale. Vol. 9(48), pp. 19086-19099. |
| Abstract: Birefringence and neutron diffraction experiments reveal an exceptional structure, phase transformation behavior and functionality in chiral mesogen/mesopore hybrids. |
BibTeX:
@article{Busch2017,
author = {Busch, Mark and Kityk, Andriy V. and Piecek, Wiktor and Hofmann, Tommy and Wallacher, Dirk and Całus, Sylwia and Kula, Przemysław and Steinhart, Martin and Eich, Manfred and Huber, Patrick},
title = {A ferroelectric liquid crystal confined in cylindrical nanopores: reversible smectic layer buckling, enhanced light rotation and extremely fast electro-optically active Goldstone excitations},
journal = {Nanoscale},
year = {2017},
volume = {9},
number = {48},
pages = {19086--19099},
url = {http://xlink.rsc.org/?DOI=C7NR07273B},
doi = {10.1039/C7NR07273B}
}
|
| Calvo-Dahlborg M, Cornide J, Tobola J, Nguyen-Manh D, Wróbel JS, Juraszek J, Jouen S and Dahlborg U (2017), "Interplay of electronic, structural and magnetic properties as the driving feature of high-entropy CoCrFeNiPd alloys", J. Phys. D. Appl. Phys., May, 2017. Vol. 50(18), pp. 185002. |
| Abstract: The structural and magnetic properties of CoCrFeyNi and CoCrFeNi-Pdx alloys earlier investigated experimentally by x-ray and neutron diffraction techniques and magnetometry have been theoretically reproduced using two complementary approaches for electronic structure calculations, i.e. the Korringa-Kohn-Rostoker method with the coherent potential approximation (KKR-CPA) and implemented in the ab initio framework of density functional theory and the Vienna ab initio simulation package (VASP) for supercell models of high-entropy alloy (HEA) structures. The comparison between experimental results and calculations of the lattice constants by both calculation methods indicate that the structure of CoCrFeyNi is well described by ordered fcc configurations. The values of local magnetic moments on Fe, Co, Cr, and Ni atoms depend not only on the Pd concentration but on chemical disordering. In the case of the CoCrFeNi-Pdx alloys, the KKR-CPA and the VASP calculations of disordered configurations reproduce the experimental values at 5 K up to equimolar composition and at 300 K above. The experimental values above the equimolar composition at 5 K are not satisfactorily reproduced by any of the calculations. The divergence between the experimental and calculated values is related to the variation of the ferromagnetic to paramagnetic transition temperature as a function of palladium content and to the existence of several phases, FeCoCr-rich above room temperature and FeCrPd-rich below, observed by diffraction and detected by microscopy and atom probe investigations. VASP calculations of a FeCrPd-rich phase effectively reproduced both the lattice constant and magnetization of the alloy above equimolar composition. An important conclusion of this work is that the combined analysis of the electronic, structural, and magnetic properties plays an important role in understanding the complexity of magnetic HEAs. |
BibTeX:
@article{Calvo-Dahlborg2017,
author = {Calvo-Dahlborg, M. and Cornide, J. and Tobola, J. and Nguyen-Manh, D. and Wróbel, J S and Juraszek, J. and Jouen, S. and Dahlborg, U.},
title = {Interplay of electronic, structural and magnetic properties as the driving feature of high-entropy CoCrFeNiPd alloys},
journal = {J. Phys. D. Appl. Phys.},
year = {2017},
volume = {50},
number = {18},
pages = {185002},
url = {https://iopscience.iop.org/article/10.1088/1361-6463/aa62ea},
doi = {10.1088/1361-6463/aa62ea}
}
|
| Casati N, Genoni A, Meyer B, Krawczuk A and MacChi P (2017), "Exploring charge density analysis in crystals at high pressure: Data collection, data analysis and advanced modelling", Acta Crystallogr. Sect. B Struct. Sci. Cryst. Eng. Mater.. Vol. 73(4), pp. 584-597. |
| Abstract: The possibility to determine electron-density distribution in crystals has been an enormous breakthrough, stimulated by a favourable combination of equipment for X-ray and neutron diffraction at low temperature, by the development of simplified, though accurate, electron-density models refined from the experimental data and by the progress in charge density analysis often in combination with theoretical work. Many years after the first successful charge density determination and analysis, scientists face new challenges, for example: (i) determination of the finer details of the electron-density distribution in the atomic cores, (ii) simultaneous refinement of electron charge and spin density or (iii) measuring crystals under perturbation. In this context, the possibility of obtaining experimental charge density at high pressure has recently been demonstrated [Casati et al. (2016). Nat. Commun.7, 10901]. This paper reports on the necessities and pitfalls of this new challenge, focusing on the species syn-1,6:8,13-biscarbonyl[14]annulene. The experimental requirements, the expected data quality and data corrections are discussed in detail, including warnings about possible shortcomings. At the same time, new modelling techniques are proposed, which could enable specific information to be extracted, from the limited and less accurate observations, like the degree of localization of double bonds, which is fundamental to the scientific case under examination.This paper reports on the determination of charge density distributions from crystals compressed at high pressure. Although much less accurate than traditional charge density analysis, these studies provide valuable information because the electronic states of molecules confined in highly condensed space are not easily predictable by theory and therefore experimental validation is a must. |
BibTeX:
@article{Casati2017,
author = {Casati, N. and Genoni, A. and Meyer, B. and Krawczuk, A. and MacChi, P.},
title = {Exploring charge density analysis in crystals at high pressure: Data collection, data analysis and advanced modelling},
journal = {Acta Crystallogr. Sect. B Struct. Sci. Cryst. Eng. Mater.},
year = {2017},
volume = {73},
number = {4},
pages = {584--597},
doi = {10.1107/S2052520617008356}
}
|
| Cieślak J and Toboła J (2017), "Electronic and magnetic properties of highly disordered Fe-based Frank Kasper-phases in view of first principles calculation and experimental study", In Alloy. Intermet. Compd. From Model. to Eng.. , pp. 196-227. |
| Abstract: Frank-Kasper phases (FK) have been originally called ‘Complex alloy structures regarded as sphere packing's' by their authors (Frank and Kasper 1958; Frank and Kasper 1959). These structures are mainly formed by transition metals, but there are also known examples of these phases which contain other elements (e.g., Al or Au), surprisingly even polymers can crystallize in s-structure (Lee et al. 2010). The most characteristic feature of these phases is the topological arrangement of atoms, ordered in such a way that each of them is located in the center of a polyhedron 197with triangular walls. There are four possible polyhedra having 20, 24, 26 or 28 faces, which correspond to the following coordination numbers: CN = 12, 14, 15 and 16. Up to now, there have been at least 27 such phases discovered in various systems, whereas some authors (Sikric et al. 2010) suggested 84 topologically possible structures undergoing definition of the FK phase. So, at least 57 new phases are still waiting for discovery. |
BibTeX:
@book{Cieslak2017,
author = {Cieslak, J. and Tobola, J.},
title = {Electronic and magnetic properties of highly disordered Fe-based Frank Kasper-phases in view of first principles calculation and experimental study},
booktitle = {Alloy. Intermet. Compd. From Model. to Eng.},
year = {2017},
pages = {196--227},
doi = {10.1201/9781315151618}
}
|
| Czub J, Przewoźnik J, Żywczak A, Takasaki A, Hoser A and Gondek (2017), "On magnetism in the quasicrystalline Ti45Zr38Ni17 alloy", J. Non. Cryst. Solids., Aug, 2017. Vol. 470, pp. 108-111. |
| Abstract: Magnetism of 3D quasicrystals is extensively researched, mainly for rare-earth or iron-based alloys. In this contribution, magnetic properties of the icosahedral Ti45Zr38Ni17 quasicrystal are reported. Namely, the results of magnetometric and neutron diffraction studies in the broad temperature ranges of 1.5–300 K and 2–700 K respectively are discussed. The magnetometric studies reveal that the alloy exhibits an extremely weak ferromagnetic signal, however it is associated with the traces of nickel clusters at the grains boundaries. The neutron scattering studies, including diffraction in external magnetic field, indicate no possibility of long-rage magnetic ordering in the icosahedral Ti45Zr38Ni17 alloy. According to our studies, the investigated material exhibits Pauli-like paramagnetic behaviour. |
BibTeX:
@article{Czub2017,
author = {Czub, J. and Przewoźnik, J. and Żywczak, A. and Takasaki, A. and Hoser, A. and Gondek},
title = {On magnetism in the quasicrystalline Ti45Zr38Ni17 alloy},
journal = {J. Non. Cryst. Solids},
year = {2017},
volume = {470},
pages = {108--111},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0022309317302594},
doi = {10.1016/j.jnoncrysol.2017.05.007}
}
|
| Ficek F, Kimball DFJ, Kozlov MG, Leefer N, Pustelny S and Budker D (2017), "Constraints on exotic spin-dependent interactions between electrons from helium fine-structure spectroscopy", Phys. Rev. A., Mar, 2017. Vol. 95(3), pp. 032505. |
| Abstract: Agreement between theoretical calculations of atomic structure and spectroscopic measurements is used to constrain possible contribution of exotic spin-dependent interactions between electrons to the energy differences between states in helium-4. In particular, constraints on dipole-dipole interactions associated with the exchange of pseudoscalar bosons (such as axions or axion-like particles) with masses 10-2"m"104eV are improved by a factor of ∼100. The first atomic-scale constraints on several exotic velocity-dependent dipole-dipole interactions are established as well. |
BibTeX:
@article{Ficek2017,
author = {Ficek, Filip and Kimball, Derek F. Jackson and Kozlov, Mikhail G. and Leefer, Nathan and Pustelny, Szymon and Budker, Dmitry},
title = {Constraints on exotic spin-dependent interactions between electrons from helium fine-structure spectroscopy},
journal = {Phys. Rev. A},
year = {2017},
volume = {95},
number = {3},
pages = {032505},
url = {https://link.aps.org/doi/10.1103/PhysRevA.95.032505},
doi = {10.1103/PhysRevA.95.032505}
}
|
| Gadalińska E, Baczmański A, Wroński S, Wróbel M, Lodini A, Klosek V and Scheffzük C (2017), "Neutron diffraction study of elastoplastic behaviour of Al/SiCp metal matrix composite", In Mater. Sci. Forum. Vol. 905 MSF, pp. 66-73. |
| Abstract: The TOF neutron diffraction measurements were done for Al/SiCp metal–matrix composite (17% of SiC) subjected to T6 thermal treatment. Using three separated diffraction peaks of SiC phase and four peaks of Al phase, the lattice strains were measured for both phases independently during in situ tensile test. The experimental results were presented in comparison with elastoplastic model, which allows to find the values of parameters determining plastic deformation of Al matrix (critical resolved shear stress and hardening parameter). Additionally, the results of TOF method were compared with those which were obtained with monochromatic neutron radiation (LLB, Saclay). In the latter experiment Al/SiCp composite containing 25% of SiC was measured. It was shown that after elastoplastic deformation the mismatch stresses determined for both phases relax during tensile deformation. |
BibTeX:
@book{Gadalinska2017,
author = {Gadalińska, E. and Baczmański, A. and Wroński, S. and Wróbel, M. and Lodini, A. and Klosek, V. and Scheffzük, C.},
title = {Neutron diffraction study of elastoplastic behaviour of Al/SiCp metal matrix composite},
booktitle = {Mater. Sci. Forum},
year = {2017},
volume = {905 MSF},
pages = {66--73},
doi = {10.4028/www.scientific.net/MSF.905.66}
}
|
| Gribkov V, Bienkowska B and Paduch M (2017), "Examination of a chamber of a large fusion facility by means of neutron activation techique with nanosecond neutron pulse generated by dense plasma focus device PF-6", Fusion Eng. Des.. Vol. 125, pp. 109-117. |
| Abstract: Analysis of neutron fields around large chambers of main-stream nuclear fusion facilities is an important problem. The neutron emission from Dense Plasma Focus (DPF) device is anisotropic itself. It may be additionally distorted by an architecture details of the hall and construction elements of a facility hosting the particular DPF setup. The compact plasma focus device PF-6 is a quasi-point source producing nanosecond pulse of about 108 2.5-MeV neutrons with narrow energy spectrum. It was used for examination of a chamber of the large plasma installation PF-1000. The construction of the PF-1000 chamber simulates neutron scattering and absorption taking place in a main-stream fusion facility. The silver-based activation monitors were used for a survey of the neutron emission field in all directions. Such a device can be further used for inertial confinement fusion (ICF) and tokamak chambers examination and for calibration of its neutron diagnostics. |
BibTeX:
@article{Gribkov2017,
author = {Gribkov, V.A. and Bienkowska, B. and Paduch, M.},
title = {Examination of a chamber of a large fusion facility by means of neutron activation techique with nanosecond neutron pulse generated by dense plasma focus device PF-6},
journal = {Fusion Eng. Des.},
year = {2017},
volume = {125},
pages = {109--117},
doi = {10.1016/j.fusengdes.2017.10.023}
}
|
| Hawelek L, Schiavon M, Szade J, Wlodarczyk P, Jurkiewicz K, Fischer H, Kolano-Burian A and Burian A (2017), "The atomic scale structure of dahlia-like single wall carbon nanohorns produced by direct vaporization of graphite", Diam. Relat. Mater.. Vol. 72, pp. 26-31. |
| Abstract: The structure of single-wall carbon nanohorns produced by direct vaporization of graphite has been studied using X-ray and neutron diffraction supported by molecular dynamics. The supplementary thermogravimetric and X-ray photoelectron spectroscopy studies have been performed to prove the structural and elemental purity of the sample. Afterwards, the pair correlation function has been calculated to represent the collected data in a real space representation. The computer-generated models consisted mainly of defected single-wall carbon nanotubes 45 Å in diameter. The calculated structure factors and pair correlation functions well reproduce the experimental data. The structural disorder in the form of topological point defects such as the Stone-Thrower-Wales, single-vacancy and double-vacancy defects have been introduced to fit the experimental data. |
BibTeX:
@article{Hawelek2017,
author = {Hawelek, L. and Schiavon, M. and Szade, J. and Wlodarczyk, P. and Jurkiewicz, K. and Fischer, H.E. and Kolano-Burian, A. and Burian, A.},
title = {The atomic scale structure of dahlia-like single wall carbon nanohorns produced by direct vaporization of graphite},
journal = {Diam. Relat. Mater.},
year = {2017},
volume = {72},
pages = {26--31},
doi = {10.1016/j.diamond.2016.12.015}
}
|
| Hetmańczyk J, Hetmańczyk Ł, Migdał-Mikuli A and Mikuli E (2017), "Crystal structure, solid-solid phase transition and thermal properties of [Mn(H2O)2](ReO4)2", J. Coord. Chem., Apr, 2017. Vol. 70(7), pp. 1190-1206. |
| Abstract: Using differential scanning calorimetry, one phase transition at TCh = 285.0 K (on heating) and TCc = 284.5 K (on cooling) was detected for [Mn(H2O)2](ReO4)2 in the temperature range 120–295 K. Sharpness of the heat flow anomaly and thermal hysteresis associated with this anomaly suggest that the detected phase transition is a first-order one. The following thermodynamic parameters for phase II ↔ phase I transition were obtained: ΔH ≈ 2.0 kJmol−1 and ΔS ≈ 6.9 Jmol-1 K−1. The latter quantity is close to Rln2, indicating some degree of molecular dynamical (configurational) disorder of the high temperature phase. X-ray single crystal diffraction and neutron powder diffraction results revealed that the phase transition discovered at TCc is associated also with a change of the crystal structure from monoclinic (space group: I2/m, No. 12) to triclinic (P-1, No. 2). Moreover one hydrogen is disordered between two possible positions in the high temperature phase. Far infrared absorption spectra registered on cooling indicate at the vicinity of TCc splitting of some degenerate vibrational modes. Additionally, one can observe a few new bands in the wavenumber ranges of 500–350 and 170–125 cm−1. |
BibTeX:
@article{Hetmanczyk2017,
author = {Hetmańczyk, Joanna and Hetmańczyk, Łukasz and Migdał-Mikuli, Anna and Mikuli, Edward},
title = {Crystal structure, solid-solid phase transition and thermal properties of [Mn(H2O)2](ReO4)2},
journal = {J. Coord. Chem.},
year = {2017},
volume = {70},
number = {7},
pages = {1190--1206},
url = {https://www.tandfonline.com/doi/full/10.1080/00958972.2017.1301439},
doi = {10.1080/00958972.2017.1301439}
}
|
| Hetmańczyk Ł and Hetmańczyk J (2017), "Dynamics of NH3 ligands and ClO4− anions in the phase transition in [Cd(NH3)6](ClO4)2 studied by x-ray powder diffraction, neutron scattering methods and infrared spectroscopy", J. Phys. Chem. Solids. Vol. 101, pp. 34-44. |
| Abstract: Phase transition, reorientational dynamics of NH3 ligands and ClO4− anions and crystal structure changes were investigated using x-ray powder diffraction (XRPD), neutron powder diffraction (NPD), quasi-elastic neutron scattering (QENS) and Fourier transform infrared spectroscopy (FT-IR). Most measurements were carried out in the temperature range 9–300 K. The diffraction techniques revealed that NH3 ligands and ClO4− anions are orientationally disordered at room temperature. During the cooling process, the high temperature cubic phase transforms into a lower symmetry phase (most probably of monoclinic structure). The QENS results confirm that NH3 ligands perform picoseconds reorientational motions both in the high and low temperature phases. This motion is almost unaffected by the observed phase transition (Tc=138.9 K on heating) and can be well described assuming the three fold jump model. On the other hand, the band shape analysis performed for the IR band connected with ClO4− internal vibration mode δd(OClO)E at 461 cm−1 clearly shows that ClO4− anions reorientate quickly in the high temperature phase, but that motion begins slowing down in the vicinity of the phase transition. Below 150 K the exponential reorientation relaxation term vanishes and only the vibrational relaxation term is present; small discontinuity is also visible. Moreover, below the phase transition temperature Tc splitting of the infrared absorption bands connected with some NH3 internal vibrations is observed. |
BibTeX:
@article{Hetmanczyk2017a,
author = {Hetmańczyk, Łukasz and Hetmańczyk, Joanna},
title = {Dynamics of NH3 ligands and ClO4− anions in the phase transition in [Cd(NH3)6](ClO4)2 studied by x-ray powder diffraction, neutron scattering methods and infrared spectroscopy},
journal = {J. Phys. Chem. Solids},
year = {2017},
volume = {101},
pages = {34--44},
doi = {10.1016/j.jpcs.2016.10.006}
}
|
| Hoser A and Madsen A (2017), "Dynamic quantum crystallography: Lattice-dynamical models refined against diffraction data. II. Applications to l -alanine, naphthalene and xylitol", Acta Crystallogr. Sect. A Found. Adv.. Vol. 73(2), pp. 102-114. |
| Abstract: In the first paper of this series [Hoser & Madsen (2016). Acta Cryst. A72, 206-214], a new approach was introduced which enables the refinement of frequencies of normal modes obtained from ab initio periodic computations against single-crystal diffraction data. In this contribution, the performance of this approach is tested by refinement against data in the temperature range from 23 to 205 K on the molecular crystals of l-alanine, naphthalene and xylitol. The models, which are lattice-dynamical models derived at the Γ point of the Brillouin zone, are able to describe the atomic vibrations of l-alanine and naphthalene to a level where the residual densities are similar to those obtained from the independent atom model. For the more flexible molecule xylitol, larger deviations are found. Hydrogen ADPs (anisotropic displacement parameters) derived from the models are in similar or better agreement with neutron diffraction results than ADPs obtained by other procedures. The heat capacity calculated after normal mode refinement for naphthalene is in reasonable agreement with the heat capacity obtained from calorimetric measurements (to less than 1 cal mol-1 K-1 below 300 K), with deviations at higher temperatures indicating anharmonicity. Standard uncertainties and correlation of the refined parameters have been derived based on a Monte Carlo procedure. The uncertainties are quite small and probably underestimated.The performance of a lattice-dynamical model refined against elastic Bragg scattering data is tested on l-alanine, naphthalene and xylitol. |
BibTeX:
@article{Hoser2017,
author = {Hoser, A.A. and Madsen, A.O.},
title = {Dynamic quantum crystallography: Lattice-dynamical models refined against diffraction data. II. Applications to l -alanine, naphthalene and xylitol},
journal = {Acta Crystallogr. Sect. A Found. Adv.},
year = {2017},
volume = {73},
number = {2},
pages = {102--114},
doi = {10.1107/S2053273316018994}
}
|
| Jaime M, Saul A, Salamon M, Zapf VS, Harrison N, Durakiewicz T, Lashley JC, Andersson DA, Stanek CR, Smith JL and Gofryk K (2017), "Piezomagnetism and magnetoelastic memory in uranium dioxide", Nat. Commun., Jul, 2017. Vol. 8(1), pp. 99. |
| Abstract: The thermal and magnetic properties of uranium dioxide, a prime nuclear fuel and thoroughly studied actinide material, remain a long standing puzzle, a result of strong coupling between magnetism and lattice vibrations. The magnetic state of this cubic material is characterized by a 3- k non-collinear antiferromagnetic structure and multidomain Jahn-Teller distortions, likely related to its anisotropic thermal properties. Here we show that single crystals of uranium dioxide subjected to strong magnetic fields along threefold axes in the magnetic state exhibit the abrupt appearance of positive linear magnetostriction, leading to a trigonal distortion. Upon reversal of the field the linear term also reverses sign, a hallmark of piezomagnetism. A switching phenomenon occurs at ±18 T, which persists during subsequent field reversals, demonstrating a robust magneto-elastic memory that makes uranium dioxide the hardest piezomagnet known. A model including a strong magnetic anisotropy, elastic, Zeeman, Heisenberg exchange, and magnetoelastic contributions to the total energy is proposed. |
BibTeX:
@article{Jaime2017,
author = {Jaime, M. and Saul, A. and Salamon, M. and Zapf, V. S. and Harrison, N. and Durakiewicz, T. and Lashley, J. C. and Andersson, D. A. and Stanek, C. R. and Smith, J. L. and Gofryk, K.},
title = {Piezomagnetism and magnetoelastic memory in uranium dioxide},
journal = {Nat. Commun.},
year = {2017},
volume = {8},
number = {1},
pages = {99},
url = {https://www.nature.com/articles/s41467-017-00096-4},
doi = {10.1038/s41467-017-00096-4}
}
|
| Jin WT, Sun J-P, Ye GZ, Xiao Y, Su Y, Schmalzl K, Nandi S, Bukowski Z, Guguchia Z, Feng E, Fu Z and Cheng J-G (2017), "Hydrostatic pressure effects on the static magnetism in Eu(Fe0.925Co0.075)2As2", Sci. Rep., Jun, 2017. Vol. 7(1), pp. 3532. |
| Abstract: EuFe 2 As 2 -based iron pnictides are quite interesting compounds, due to the two magnetic sublattices in them and the tunability to superconductors by chemical doping or application of external pressure. The effects of hydrostatic pressure on the static magnetism in Eu(Fe 0.925 Co 0.075 ) 2 As 2 are investigated by complementary electrical resistivity, ac magnetic susceptibility and single-crystal neutron diffraction measurements. A specific pressure-temperature (P-T) phase diagram of Eu(Fe 0.925 Co 0.075 ) 2 As 2 is established. The structural phase transition, as well as the spin-density-wave order of Fe sublattice, is suppressed gradually with increasing pressure and disappears completely above 2.0 GPa. In contrast, the magnetic order of Eu sublattice persists over the whole investigated pressure range up to 14 GPa, yet displaying a non-monotonic variation with pressure. With the increase of the hydrostatic pressure, the magnetic state of Eu evolves from the canted antiferromagnetic structure in the ground state, via a pure ferromagnetic structure under the intermediate pressure, finally to an “unconfirmed” antiferromagnetic structure under the high pressure. The strong ferromagnetism of Eu coexists with the pressure-induced superconductivity around 2 GPa. Comparisons between the P-T phase diagrams of Eu(Fe 0.925 Co 0.075 ) 2 As 2 and the parent compound EuFe 2 As 2 were also made. |
BibTeX:
@article{Jin2017,
author = {Jin, W. T. and Sun, J.-P. and Ye, G. Z. and Xiao, Y. and Su, Y. and Schmalzl, K. and Nandi, S. and Bukowski, Z. and Guguchia, Z. and Feng, E. and Fu, Z. and Cheng, J.-G.},
title = {Hydrostatic pressure effects on the static magnetism in Eu(Fe0.925Co0.075)2As2},
journal = {Sci. Rep.},
year = {2017},
volume = {7},
number = {1},
pages = {3532},
url = {https://www.nature.com/articles/s41598-017-03762-1},
doi = {10.1038/s41598-017-03762-1}
}
|
| Klimkowicz A, Świerczek K, Zheng K, Wallacher D and Takasaki A (2017), "Oxygen release from BaLnMn2O6 (Ln: Pr, Nd, Y) under reducing conditions as studied by neutron diffraction", J. Mater. Sci.. Vol. 52(11), pp. 6476-6485. |
| Abstract: Selected A-site cation-ordered BaLnMn2O6 were investigated by neutron diffraction technique in terms of the structural modification ongoing with the oxygen release during annealing in reducing conditions. Kinetics of the structural transformations between oxidized BaLnMn2O6 (O6), partially reduced BaLnMn2O5.5 (O5.5) and fully reduced BaLnMn2O5 (O5) were measured in 200–500 °C range in 5 vol% H2 in Ar. Studies revealed that both O6–O5.5 and O5.5–O5 transitions for all samples occur according to a two-phase mechanism, but the phases undergo slight modification of their structural parameters. The Y-containing material showed decreased tendency of formation of oxygen vacancy-ordered BaYMn2O5.5. Moreover, kinetics of the transitions for Pr- and Nd-containing oxides was found to be more constrained by surface reaction and nucleation processes at the initial stage, while the following oxygen release from O5.5 phase was found to be limited rather by the oxygen diffusion, which is in opposite to BaYMn2O5+δ. The obtained results indicate that ionic radius of Ln3+ has a direct influence on the mechanism of the oxygen release process from BaLnMn2O6, influencing the oxygen storage-related performance. |
BibTeX:
@article{Klimkowicz2017,
author = {Klimkowicz, Alicja and Świerczek, Konrad and Zheng, Kun and Wallacher, Dirk and Takasaki, Akito},
title = {Oxygen release from BaLnMn2O6 (Ln: Pr, Nd, Y) under reducing conditions as studied by neutron diffraction},
journal = {J. Mater. Sci.},
year = {2017},
volume = {52},
number = {11},
pages = {6476--6485},
doi = {10.1007/s10853-017-0883-2}
}
|
| Knychała P, Timachova K, Banaszak M and Balsara N (2017), "50th Anniversary Perspective: Phase Behavior of Polymer Solutions and Blends", Macromolecules. Vol. 50(8), pp. 3051-3065. |
| Abstract: We summarize our knowledge of the phase behavior of polymer solutions and blends using a unified approach. We begin with a derivation of the Flory-Huggins expression for the Gibbs free energy of mixing two chemically dissimilar polymers. The Gibbs free energy of mixing of polymer solutions is obtained as a special case. These expressions are used to interpret observed phase behavior of polymer solutions and blends. Temperature- and pressure-dependent phase diagrams are used to determine the Flory-Huggins interaction parameter, χ. We also discuss an alternative approach for measuring χ due to de Gennes, who showed that neutron scattering from concentration fluctuations in one-phase systems was a sensitive function of χ. In most cases, the agreement between experimental data and the standard Flory-Huggins-de Gennes approach is qualitative. We conclude by summarizing advanced theories that have been proposed to address the limitations of the standard approach. In spite of considerable effort, there is no consensus on the reasons for departure between the standard theories and experiments. |
BibTeX:
@article{Knychaa2017,
author = {Knychała, P. and Timachova, K. and Banaszak, M. and Balsara, N.P.},
title = {50th Anniversary Perspective: Phase Behavior of Polymer Solutions and Blends},
journal = {Macromolecules},
year = {2017},
volume = {50},
number = {8},
pages = {3051--3065},
doi = {10.1021/acs.macromol.6b02619}
}
|
| Kozik T, Śniechowski M, Łużny W, Proń A and Djurado D (2017), "Neutron diffraction study of conducting polyaniline doped with (±) camphorsulfonic acid", Polymer (Guildf).. Vol. 111, pp. 148-155. |
| Abstract: Fully hydrogenated and partially deuterated free standing films of polyaniline doped with (±) camphorsulfonic acid (PANIh5/CSA and PANId4/CSA) are subjected to neutron diffraction study. Obtained results are analyzed and compared with X-ray diffraction measurements. The very distinct differences observed between the two neutron diffraction profiles are described in detail. Making use of the recently published new model of the crystalline structure of the PANI/CSA system, the neutron diffraction curves for the analogous structures are calculated. The two calculated neutron diffraction patterns exhibit similar differences as those obtained in experiment. This fully confirms the validity of the refined molecular model elaborated for this still important material for applications as synthetic metals or organic thermoelectrics. |
BibTeX:
@article{Kozik2017,
author = {Kozik, T. and Śniechowski, M. and Łużny, W. and Proń, A. and Djurado, D.},
title = {Neutron diffraction study of conducting polyaniline doped with (±) camphorsulfonic acid},
journal = {Polymer (Guildf).},
year = {2017},
volume = {111},
pages = {148--155},
doi = {10.1016/j.polymer.2017.01.034}
}
|
| Król D, da Silva R, Deelman E and Lynch V (2017), "Workflow performance profiles: Development and analysis", In Lect. Notes Comput. Sci. (including Subser. Lect. Notes Artif. Intell. Lect. Notes Bioinformatics). Vol. 10104 LNCS, pp. 108-120. |
| Abstract: This paper presents a method for performance profiles development of scientific workflow. It addresses issues related to: workflows execution in a parameter sweep manner, collecting performance information about each workflow task, and analysis of the collected data with statistical learning methods. The main goal of this work is to increase the understanding about the performance of studied workflows in a systematic and predictable way. The evaluation of the presented approach is based on a real scientific workflow developed by the Spallation Neutron Source - a DOE research facility at the Oak Ridge National Laboratory. The workflow executes an ensemble of molecular dynamics and neutron scattering intensity calculations to optimize a model parameter value. |
BibTeX:
@book{Krol2017,
author = {Król, D. and da Silva, R.F. and Deelman, E. and Lynch, V.E.},
title = {Workflow performance profiles: Development and analysis},
booktitle = {Lect. Notes Comput. Sci. (including Subser. Lect. Notes Artif. Intell. Lect. Notes Bioinformatics)},
year = {2017},
volume = {10104 LNCS},
pages = {108--120},
doi = {10.1007/978-3-319-58943-5_9}
}
|
| Krzystyniak M, Druzbicki K, Romanelli G, Gutmann M, Rudić S, Imberti S and Fernandez-Alonso F (2017), "Nuclear dynamics and phase polymorphism in solid formic acid", Phys. Chem. Chem. Phys.. Vol. 19(13), pp. 9064-9074. |
| Abstract: We apply a unique sequence of structural and dynamical neutron-scattering techniques, augmented with density-functional electronic-structure calculations, to establish the degree of polymorphism in an archetypal hydrogen-bonded system-crystalline formic acid. Using this combination of experimental and theoretical techniques, the hypothesis by Zelsmann on the coexistence of the β1 and β2 phases above 220 K is tested. Contrary to the postulated scenario of proton-transfer-driven phase coexistence, the emerging picture is one of a quantitatively different structural change over this temperature range, whereby the loosening of crystal packing promotes temperature-induced shearing of the hydrogen-bonded chains. The presented work, therefore, solves a fifty-year-old puzzle and provides a suitable framework for the use neutron-Compton-scattering techniques in the exploration of phase polymorphism in condensed matter. |
BibTeX:
@article{Krzystyniak2017,
author = {Krzystyniak, M. and Druzbicki, K. and Romanelli, G. and Gutmann, M.J. and Rudić, S. and Imberti, S. and Fernandez-Alonso, F.},
title = {Nuclear dynamics and phase polymorphism in solid formic acid},
journal = {Phys. Chem. Chem. Phys.},
year = {2017},
volume = {19},
number = {13},
pages = {9064--9074},
doi = {10.1039/c7cp00997f}
}
|
| Kuchin AG, Platonov SP, Voronin VI, Iwasieczko W, Korolev AV, Volegov AS, Neznakhin DS, Protasov AV, Berger IF, Kolodkin DA and Proskurnina NV (2017), "Influence of microdeformations on magnetic phase transitions in the (TmxPr1-x)2Fe17 system", J. Alloys Compd.. Vol. 726, pp. 330-337. |
| Abstract: Crystal structure and magnetic and thermomagnetic properties of the (TmxPr1-x)2Fe17 system have been studied. The alloys with x = 0–0.4 and x = 0.8–1 crystallize into a rhombohedral structure of the Th2Zn17-type and into a hexagonal structure of the Th2Ni17-type, respectively. Both these structures coexist in the concentration range x = 0.5–0.75. The compounds with 0 < x < 0.6 are ferrimagnets, while in the compounds with x = 0.6–1, an additional high-temperature helimagnetic state appears. The lattice parameters, spontaneous magnetization, and the peak entropy change -ΔSM of the (TmxPr1-x)2Fe17 system decrease with increasing Tm content. The temperatures of helimagnetic ordering and ferrimagnet-to-helimagnet transition decrease non-monotonically as Tm content increases, with the minimum values being for the composition with x = 0.8. Microdeformations in the alloys with x = 0.5–0.9 have been detected by means of neutron diffraction. |
BibTeX:
@article{Kuchin2017,
author = {Kuchin, A. G. and Platonov, S. P. and Voronin, V. I. and Iwasieczko, W. and Korolev, A. V. and Volegov, A. S. and Neznakhin, D. S. and Protasov, A. V. and Berger, I. F. and Kolodkin, D. A. and Proskurnina, N. V.},
title = {Influence of microdeformations on magnetic phase transitions in the (TmxPr1-x)2Fe17 system},
journal = {J. Alloys Compd.},
year = {2017},
volume = {726},
pages = {330--337},
doi = {10.1016/j.jallcom.2017.08.016}
}
|
| Lutz P, Aguilà D, Mondal A, Pinkowicz D, Marx R, Neugebauer P, Fåk B, Ollivier J, Clérac R and van Slageren J (2017), "Elementary excitations in single-chain magnets", Phys. Rev. B., Sep, 2017. Vol. 96(9), pp. 094415. |
| Abstract: Single-chain magnets (SCMs) are one-dimensional coordination polymers or spin chains that display slow relaxation of the magnetization. Typically their static magnetic properties are described by the Heisenberg model, while the description of their dynamic magnetic properties is based on an Ising-like model. The types of excitations predicted by these models (collective vs localized) are quite different. Therefore we probed the nature of the elementary excitations for two SCMs abbreviated Mn2Ni and Mn2Fe, as well as a mononuclear derivative of the Mn2Fe chain, by means of high-frequency electron paramagnetic resonance spectroscopy (HFEPR) and inelastic neutron scattering (INS). We find that the HFEPR spectra of the chains are clearly distinct from those of the monomer. The momentum transfer dependence of the INS intensity did not reveal significant dispersion, indicating an essentially localized nature of the excitations. At the lowest temperatures these are modified by the occurrence of short-range correlations. |
BibTeX:
@article{Lutz2017,
author = {Lutz, Philipp and Aguilà, David and Mondal, Abhishake and Pinkowicz, Dawid and Marx, Raphael and Neugebauer, Petr and Fåk, Björn and Ollivier, Jacques and Clérac, Rodolphe and van Slageren, Joris},
title = {Elementary excitations in single-chain magnets},
journal = {Phys. Rev. B},
year = {2017},
volume = {96},
number = {9},
pages = {094415},
url = {https://link.aps.org/doi/10.1103/PhysRevB.96.094415},
doi = {10.1103/PhysRevB.96.094415}
}
|
| Malaspina L, Edwards A, Woińska M, Jayatilaka D, Turner M, Price J, Herbst-Irmer R, Sugimoto K, Nishibori E and Grabowsky S (2017), "Predicting the Position of the Hydrogen Atom in the Short Intramolecular Hydrogen Bond of the Hydrogen Maleate Anion from Geometric Correlations", Cryst. Growth Des.. Vol. 17(7), pp. 3812-3825. |
| Abstract: The position of the hydrogen atom inside the strong and short intramolecular hydrogen bond of the hydrogen maleate anion strongly varies depending on the crystalline environment. Therefore, it has not been possible in the past to accurately determine it using X-ray diffraction data although there are 292 hydrogen maleate crystal structures with different cations in the literature. In this study, a geometric correlation for the accurate prediction of the hydrogen position in the short intramolecular hydrogen bond is presented. The results used to derive the correlation are obtained from low-temperature neutron-diffraction studies on nine different hydrogen maleate salts that span the whole range from perfectly symmetric to highly asymmetric intramolecular hydrogen bonds. Since the only variable in the correlation as derived from the neutron data is the OtextperiodcenteredtextperiodcenteredtextperiodcenteredO distance, the hydrogen atom position in question can subsequently be predicted using information that is accurately available from routine X-ray data. The procedure is tested using high-resolution low-temperature synchrotron X-ray diffraction structures of the same compounds, before it is applied to X-ray data sets found in the literature in which the hydrogen atom position was not determined accurately or not determined at all, e.g., using a riding model. |
BibTeX:
@article{Malaspina2017,
author = {Malaspina, L.A. and Edwards, A.J. and Woińska, M. and Jayatilaka, D. and Turner, M.J. and Price, J.R. and Herbst-Irmer, R. and Sugimoto, K. and Nishibori, E. and Grabowsky, S.},
title = {Predicting the Position of the Hydrogen Atom in the Short Intramolecular Hydrogen Bond of the Hydrogen Maleate Anion from Geometric Correlations},
journal = {Cryst. Growth Des.},
year = {2017},
volume = {17},
number = {7},
pages = {3812--3825},
doi = {10.1021/acs.cgd.7b00390}
}
|
| Mihalik M, Mihalik M, Hoser A, Pajerowski DM, Kriegner D, Legut D, Lebecki KM, Vavra M, Fitta M and Meisel MW (2017), "Magnetic structure of the mixed antiferromagnet NdMn0.8Fe0.2 O3", Phys. Rev. B., Oct, 2017. Vol. 96(13), pp. 134430. |
| Abstract: The magnetic structure of the mixed
antiferromagnet NdMn0.8Fe0.2O3 was resolved. Neutron powder
diffraction data definitively resolve the Mn sublattice with a
magnetic propagation vector k=(000) and with the magnetic structure
(Ax,Fy,Gz) for 1.6 K |
BibTeX:
@article{Mihalik2017,
author = {Mihalik, Matúš and Mihalik, Marián and Hoser, Andreas and Pajerowski, Daniel M. and Kriegner, Dominik and Legut, Dominik and Lebecki, Kristof M. and Vavra, Martin and Fitta, Magdalena and Meisel, Mark W.},
title = {Magnetic structure of the mixed antiferromagnet NdMn0.8Fe0.2 O3},
journal = {Phys. Rev. B},
year = {2017},
volume = {96},
number = {13},
pages = {134430},
url = {https://link.aps.org/doi/10.1103/PhysRevB.96.134430},
doi = {10.1103/PhysRevB.96.134430}
}
|
| Minns JL, Zajdel P, Chernyshov D, van Beek W and Green MA (2017), "Structure and interstitial iodide migration in hybrid perovskite methylammonium lead iodide", Nat. Commun., May, 2017. Vol. 8(1), pp. 15152. |
| Abstract: Hybrid perovskites form an emerging family of exceptional light harvesting compounds. However, the mechanism underpinning their photovoltaic effect is still far from understood, which is impeded by a lack of clarity on their structures. Here we show that iodide ions in the methylammonium lead iodide migrate via interstitial sites at temperatures above 280 K. This coincides with temperature dependent static distortions resulting in pseudocubic local symmetry. Based on bond distance analysis, the migrating and distorted iodines are at lengths consistent with the formation of I 2 molecules, suggesting a 2I − →I 2 +2 e − redox couple. The actual formula of this compound is thus (CH 3 NH 3 )PbI 3−2 x (I 2 ) x where x ∼0.007 at room temperature. A crucial feature of the tetragonal structure is that the methylammonium ions do not sit centrally in the A-site cavity, but disordered around two off-centre orientations that facilitate the interstitial ion migration via a gate opening mechanism. |
BibTeX:
@article{Minns2017,
author = {Minns, J. L. and Zajdel, P. and Chernyshov, D. and van Beek, W. and Green, M. A.},
title = {Structure and interstitial iodide migration in hybrid perovskite methylammonium lead iodide},
journal = {Nat. Commun.},
year = {2017},
volume = {8},
number = {1},
pages = {15152},
url = {https://www.nature.com/articles/ncomms15152},
doi = {10.1038/ncomms15152}
}
|
| Niebuur B-J, Claude K-L, Pinzek S, Cariker C, Raftopoulos K, Pipich V, Appavou M-S, Schulte A and Papadakis C (2017), "Pressure-Dependence of Poly(N-isopropylacrylamide) Mesoglobule Formation in Aqueous Solution", ACS Macro Lett.. Vol. 6(11), pp. 1180-1185. |
| Abstract: Above their cloud point, aqueous solutions of the thermoresponsive polymer poly(N-isopropylacrylamide) (PNIPAM) form large mesoglobules. We have carried out very small-angle neutron scattering (VSANS with q = 0.21-2.3 × 10-3 Å-1) and Raman spectroscopy experiments on a 3 wt % PNIPAM solution in D2O at atmospheric and elevated pressures (up to 113 MPa). Raman spectroscopy reveals that, at high pressure, the polymer is less dehydrated upon crossing the cloud point. VSANS shows that the mesoglobules are significantly larger and contain more D2O than at atmospheric pressure. We conclude that the size of the mesoglobules and thus their growth process are closely related to the hydration state of PNIPAM. |
BibTeX:
@article{Niebuur2017,
author = {Niebuur, B.-J. and Claude, K.-L. and Pinzek, S. and Cariker, C. and Raftopoulos, K.N. and Pipich, V. and Appavou, M.-S. and Schulte, A. and Papadakis, C.M.},
title = {Pressure-Dependence of Poly(N-isopropylacrylamide) Mesoglobule Formation in Aqueous Solution},
journal = {ACS Macro Lett.},
year = {2017},
volume = {6},
number = {11},
pages = {1180--1185},
doi = {10.1021/acsmacrolett.7b00563}
}
|
| Patel T, Chojnowski G, Astha, Koul A, McKenna S and Bujnicki J (2017), "Structural studies of RNA-protein complexes: A hybrid approach involving hydrodynamics, scattering, and computational methods", Methods. Vol. 118-119, pp. 146-162. |
| Abstract: The diverse functional cellular roles played by ribonucleic acids (RNA) have emphasized the need to develop rapid and accurate methodologies to elucidate the relationship between the structure and function of RNA. Structural biology tools such as X-ray crystallography and Nuclear Magnetic Resonance are highly useful methods to obtain atomic-level resolution models of macromolecules. However, both methods have sample, time, and technical limitations that prevent their application to a number of macromolecules of interest. An emerging alternative to high-resolution structural techniques is to employ a hybrid approach that combines low-resolution shape information about macromolecules and their complexes from experimental hydrodynamic (e.g. analytical ultracentrifugation) and solution scattering measurements (e.g., solution X-ray or neutron scattering), with computational modeling to obtain atomic-level models. While promising, scattering methods rely on aggregation-free, monodispersed preparations and therefore the careful development of a quality control pipeline is fundamental to an unbiased and reliable structural determination. This review article describes hydrodynamic techniques that are highly valuable for homogeneity studies, scattering techniques useful to study the low-resolution shape, and strategies for computational modeling to obtain high-resolution 3D structural models of RNAs, proteins, and RNA-protein complexes. |
BibTeX:
@article{Patel2017,
author = {Patel, T.R. and Chojnowski, G. and Astha and Koul, A. and McKenna, S.A. and Bujnicki, J.M.},
title = {Structural studies of RNA-protein complexes: A hybrid approach involving hydrodynamics, scattering, and computational methods},
journal = {Methods},
year = {2017},
volume = {118-119},
pages = {146--162},
doi = {10.1016/j.ymeth.2016.12.002}
}
|
| Paul-Boncour V, Filipek SM, Provost K, Couturas F and Morawski A (2017), "Structural and magnetic phase diagram of YMn2−xFex(H,D)ycompounds (5 ≤ y ≤ 6) synthesized under high H or D gaseous pressure", J. Alloys Compd., Jan, 2017. Vol. 691, pp. 884-892. |
| Abstract: YMn2−xFexH(D)ycompounds with high hydrogen or deuterium content (5 ≤ y ≤ 6) were synthesized under high H or D gaseous pressure (P ≈ 0.8 GPa) at 373 K, in order to determine their structural and magnetic phase diagram. For high Mn content (x < 1) they form complex hydrides (deuterides) with y = 6 and crystallize in a cubic K2PtCl6structure (Fm-3m space group). For 0.2 ≤ x < 1 the complex hydrides coexist with metal hydrides (y = 5) crystallizing in a cubic MgCu2type structure (Fd-3m space group). Single phase hydrides with MgCu2type structure are obtained for 1 ≤ x ≤ 1.5 with interstitial H(D) atoms localized in tetrahedral Y2(Mn,Fe)2sites (y = 5). The cubic cell volume decreases versus Fe content and is 1.4% larger for the hydride compared to the corresponding deuteride. For x > 1.5 the compounds display an orthorhombic distortion (Pmn21space group) which is due to H or D ordering in 8 interstitial sites. The magnetic measurements of hydrides and deuterides show a decrease of the magnetization compared to their parent compounds whereas a large irreversibility is observed below the magnetic ordering temperature which depends on the Fe content. Neutron diffraction measurements at 2 and 300 K reveal the existence of only short range order magnetic interactions. |
BibTeX:
@article{Paul-Boncour2017,
author = {Paul-Boncour, V. and Filipek, S. M. and Provost, K. and Couturas, F. and Morawski, A.},
title = {Structural and magnetic phase diagram of YMn2−xFex(H,D)ycompounds (5 ≤ y ≤ 6) synthesized under high H or D gaseous pressure},
journal = {J. Alloys Compd.},
year = {2017},
volume = {691},
pages = {884--892},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838816326585},
doi = {10.1016/j.jallcom.2016.08.258}
}
|
| Poznar M, Hołubowicz R, Wojtas M, Gapiński J, Banachowicz E, Patkowski A, Ożyhar A and Dobryszycki P (2017), "Structural properties of the intrinsically disordered, multiple calcium ion-binding otolith matrix macromolecule-64 (OMM-64)", Biochim. Biophys. Acta - Proteins Proteomics. Vol. 1865(11), pp. 1358-1371. |
| Abstract: Fish otoliths are calcium carbonate biominerals that are involved in hearing and balance sensing. An organic matrix plays a crucial role in their formation. Otolith matrix macromolecule-64 (OMM-64) is a highly acidic, calcium-binding protein (CBP) found in rainbow trout otoliths. It is a component of high-molecular-weight aggregates, which influence the size, shape and polymorph of calcium carbonate in vitro. In this study, a protocol for the efficient expression and purification of OMM-64 was developed. For the first time, the complete structural characteristics of OMM-64 were described. Various biophysical methods were combined to show that OMM-64 occurs as an intrinsically disordered monomer. Under denaturing conditions (pH, temperature) OMM-64 exhibits folding propensity. It was determined that OMM-64 binds approximately 61 calcium ions with millimolar affinity. The folding-unfolding experiments showed that calcium ions induced the collapse of OMM-64. The effect of other counter ions present in trout endolymph on OMM-64 conformational changes was studied. The significance of disordered properties of OMM-64 and the possible function of this protein is discussed. |
BibTeX:
@article{Poznar2017,
author = {Poznar, M. and Hołubowicz, R. and Wojtas, M. and Gapiński, J. and Banachowicz, E. and Patkowski, A. and Ożyhar, A. and Dobryszycki, P.},
title = {Structural properties of the intrinsically disordered, multiple calcium ion-binding otolith matrix macromolecule-64 (OMM-64)},
journal = {Biochim. Biophys. Acta - Proteins Proteomics},
year = {2017},
volume = {1865},
number = {11},
pages = {1358--1371},
doi = {10.1016/j.bbapap.2017.08.019}
}
|
| Rajewska A, Kh Islamov A and Bakeeva RF (2017), "SANS method study of surfactant mixture system TX-100+C16TAB in heavy water solutions", J. Phys. Conf. Ser., May, 2017. Vol. 848(1), pp. 012023. |
| Abstract: The mixture system of two classic surfactants cationic and non-ionic - C16TAB (hexadecyltrimethylammonium bromide)+TX-100(p-(1,1,3,3-tetramethyl) poly(oxyethylene) in heavy water solutions was investigated at temperatures 30o, 50o, 70o for compositions 1:1, 2:1, 3:1 by the small-angle neutron scattering(SANS) method on spectrometer ('YuMO') at the IBR-2 pulsed neutron source at FLNP, JINR in Dubna (Russia). Measurements have covered Q range from 7x10-3 to 0.4 Å -1. The SANS measurements of aqueous solutions of nonionic / cationic surfactants have shown that the mixed micelles are formed [1-2]. From the measured dependence of the scattered intensity on the scattering angle, we derived the size, shape of micelles, aggregation number at various compositions and temperatures. The size of mixed micelle is a weak function of the mixing ratio between the two components. |
BibTeX:
@article{Rajewska2017,
author = {Rajewska, A. and Kh Islamov, A. and Bakeeva, R F},
title = {SANS method study of surfactant mixture system TX-100+C16TAB in heavy water solutions},
journal = {J. Phys. Conf. Ser.},
year = {2017},
volume = {848},
number = {1},
pages = {012023},
url = {https://iopscience.iop.org/article/10.1088/1742-6596/848/1/012023},
doi = {10.1088/1742-6596/848/1/012023}
}
|
| Serrano M, Álvarez-Pérez J, Zaldo C, Sanz J, Sobrados I, Alonso J, Cascales C, Fernández-Díaz M and Jezowski A (2017), "Design of Yb3+ optical bandwidths by crystallographic modification of disordered calcium niobium gallium laser garnets", J. Mater. Chem. C. Vol. 5(44), pp. 11481-11495. |
| Abstract: Ca□3[Nb1-xGax□]2(Ga1-yNby□)3O12-type cubic Ia3d garnets (CNGG) have been grown by the Czochralski method, either unmodified or incorporating different crystalline modifiers (Li+ or Mg2+), and Yb3+ as a laser dopant. From nuclear magnetic resonance, single crystal X-ray and powder neutron diffraction studies it is shown that Li+ incorporates exclusively into the 24d tetrahedral site of the host, removing tetrahedral-sited Nb5+ and filling cationic vacancies in this site. A comparison of low temperature (6 K) Yb3+ spectroscopy in crystals with different compositions at the tetrahedral sites and a modeling of energy positions of the 2F7/2(0) and 2F5/2(0′) Yb3+ levels show that the strongest contribution to the Yb3+ optical absorption/emission bandwidth is associated with the electric charge of cations/vacancies occupying the two tetrahedra at the shortest distance (3.12 Å) from the central 24c dodecahedral Yb3+. Cationic disorder over the remaining four tetrahedral, octahedral and dodecahedral sites also contributes to the Yb3+ bandwidth but to a lesser extent. To obtain the largest Yb3+ bandwidth, the two nearest tetrahedra must contain cations/vacancies with electric charges as different as possible. Although the decrease in the concentration of vacancies at tetrahedral sites associated with Li+ incorporation induces some reduction of the Yb3+ optical bandwidth with regard to the unmodified Yb:CNGG crystal, Li+ incorporation along with the use of high purity precursors yields crystals with less coloration, longer Yb3+ lifetime, and slightly larger thermal conductivity, which favors laser operation performance. |
BibTeX:
@article{Serrano2017,
author = {Serrano, M.D. and Álvarez-Pérez, J.O. and Zaldo, C. and Sanz, J. and Sobrados, I. and Alonso, J.A. and Cascales, C. and Fernández-Díaz, M.T. and Jezowski, A.},
title = {Design of Yb3+ optical bandwidths by crystallographic modification of disordered calcium niobium gallium laser garnets},
journal = {J. Mater. Chem. C},
year = {2017},
volume = {5},
number = {44},
pages = {11481--11495},
doi = {10.1039/c7tc02760e}
}
|
| Sheka E and Natkaniec I (2017), "Neutron scattering of parent and reduced graphene oxides", Rev. Adv. Mater. Sci.. Vol. 49(1), pp. 1-27. |
| Abstract: The current paper summarizes results of an extended neutron scattering study of a three-part set of parent and reduced graphene oxide (GO and rGO, respectively) of different origin. The first part concerned the rGO of natural origin presented by wet and dry shungite carbons [1,2], the second was related to synthetic GO and rGO with the latter produced in the course of chemical treatment [3], the third part presents another pair of synthetic GO/rGO products with the latter produced via thermo exfoliation of the parent GO [4]. The study involved both the neutron diffraction (ND) and inelastic neutron scattering (INS). The neutron diffraction patterns confirmed stacking structures of all the species consisting of a number of layers of nanosize (natural products) and microsize (synthetic products) lateral dimension and the interlayer distances of 7.0-7.2 Å and 3.4-3.5 Å for GO and rGO, respectively. One-phonon amplitude-weighted density of vibrational states G(ω) represents the inelastic incoherent neutron scattering spectra of the products. The obtained data are analyzed basing on calculated G(ω) functions. The performed study has convincingly shown that neutron scattering clearly distinguishes GO and rGO species and well exhibits both common features and differences related to the members of the two communities. If retained water in GOs and graphene-hydride nature of rGOs provide the commonality of dynamic properties within each of the community, the difference in the relevant sheet topology is responsible for a noticeable variability of the latter. The study has convincingly shown a large polyvariance of both GO and rGO products evidencing their topochemical nature. |
BibTeX:
@article{Sheka2017,
author = {Sheka, E.F. and Natkaniec, I.},
title = {Neutron scattering of parent and reduced graphene oxides},
journal = {Rev. Adv. Mater. Sci.},
year = {2017},
volume = {49},
number = {1},
pages = {1--27}
}
|
| Shmakov A, Cherepanova S, Zyuzin D, Fedorova Y, Bobrikov I, Roger A-C, Adamski A and Sadykov V (2017), "The crystal structure of compositionally homogeneous mixed ceria-zirconia oxides by high resolution X-ray and neutron diffraction methods", Open Chem.. Vol. 15(1), pp. 438-445. |
| Abstract: The real/atomic structure of single phase homogeneous nanocrystalline Ce0.5Zr0.5O2±δ oxides prepared by a modified Pechini route and Ni-loaded catalysts of methane dry reforming on their bases was studied by a combination of neutron diffraction, synchrotron X-ray diffraction, total X-ray scattering and X-ray absorption spectroscopy. The effects of sintering temperature and pretreatment in H2 were elucidated. The structure of the mixed oxides corresponds to a tetragonal space group indicating a homogeneous distribution of Ce and Zr cations in the lattice. A pronounced disordering of the oxygen sublattice was revealed by neutron diffraction, supposedly due to incorporation of water into the structure when in contact with air promoted by the generation of anion vacancies in the lattice after reduction or calcination at high temperatures. However, such disordering has not resulted in any occupation of the oxygen interstitial positions in the bulk of the nanodomains. |
BibTeX:
@article{Shmakov2017,
author = {Shmakov, A.N. and Cherepanova, S.V. and Zyuzin, D.A. and Fedorova, Y.E. and Bobrikov, I.A. and Roger, A.-C. and Adamski, A. and Sadykov, V.A.},
title = {The crystal structure of compositionally homogeneous mixed ceria-zirconia oxides by high resolution X-ray and neutron diffraction methods},
journal = {Open Chem.},
year = {2017},
volume = {15},
number = {1},
pages = {438--445},
doi = {10.1515/chem-2017-0044}
}
|
| Szeleszczuk Ł, Gubica T, Zimniak A, Pisklak D, Dabrowska K, Cyrański M and Kańska M (2017), "The potential for the indirect crystal structure verification of methyl glycosides based on acetates' parent structures: GIPAW and solid-state NMR approaches", Chem. Phys. Lett.. Vol. 686, pp. 7-11. |
| Abstract: A convenient method for the indirect crystal structure verification of methyl glycosides was demonstrated. Single-crystal X-ray diffraction structures for methyl glycoside acetates were deacetylated and subsequently subjected to DFT calculations under periodic boundary conditions. Solid-state NMR spectroscopy served as a guide for calculations. A high level of accuracy of the modelled crystal structures of methyl glycosides was confirmed by comparison with published results of neutron diffraction study using RMSD method. |
BibTeX:
@article{Szeleszczuk2017,
author = {Szeleszczuk, Ł. and Gubica, T. and Zimniak, A. and Pisklak, D.M. and Dabrowska, K. and Cyrański, M.K. and Kańska, M.},
title = {The potential for the indirect crystal structure verification of methyl glycosides based on acetates' parent structures: GIPAW and solid-state NMR approaches},
journal = {Chem. Phys. Lett.},
year = {2017},
volume = {686},
pages = {7--11},
doi = {10.1016/j.cplett.2017.08.028}
}
|
| Szytuła A, Baran S, Jaworska-Gołab T, Marzec M, Deptuch A, Tyvanchuk Y, Penc B, Hoser A, Sivachenko A, Val'kov V, Dyakonov V and Szymczak H (2017), "Influence of Cr doping on magnetocaloric effect and physical properties of slowly cooled NiMn1−xCrxGe", J. Alloys Compd., Dec, 2017. Vol. 726, pp. 978-988. |
| Abstract: Slowly cooled NiMn1−xCrxGe (x = 0.04, 0.11, 0.18 and 0.25) has been studied by X-ray (90–480 K) and neutron diffraction (1.6–400 K), differential scanning calorimetry (300–480 K) and magnetic (2.0–400 K, magnetic field up to 90 kOe) measurements. The compounds undergo a martensitic phase transition changing their crystal structure between the orthorhombic low temperature phase (space group Pnma) and the hexagonal high temperature one (space group P63/mmc). The temperature of the structural phase transition significantly decreases with increasing x (TS = 464 K for x = 0.04 and 373 K for 0.25 on heating and similarly TS = 445 K for x = 0.04 and 355 K for 0.25 on cooling). Antiferromagnetic helicoidal ordering with the propagation vector k = (kx, 0, 0) for x = 0.04 and 0.11 (TN = 357 and 353 K, respectively) and ferromagnetic one for x = 0.25 (TC = 360 K) has been found. The sample with x = 0.18 shows a coexistence of a helicoidal antiferromagnetic structure and the ferromagnetic one below ∼170 K while at higher temperatures the ferromagnetic ordering remains stable up to 362 K. For all investigated samples the magnetocaloric effect is observed. Maximum entropy change (−ΔS) increases with increasing Cr concentration from about 8 J/(kg K) at 90 kOe, found for x = 0.04 and 0.11 at the Néel temperature, up to 29 J/(kg K) observed for x = 0.25 in cooling regime at the magnetostructural phase transition temperature. |
BibTeX:
@article{Szytua2017,
author = {Szytuła, A. and Baran, S. and Jaworska-Gołab, T. and Marzec, M. and Deptuch, A. and Tyvanchuk, Yu and Penc, B. and Hoser, A. and Sivachenko, A. and Val'kov, V. and Dyakonov, V. and Szymczak, H.},
title = {Influence of Cr doping on magnetocaloric effect and physical properties of slowly cooled NiMn1−xCrxGe},
journal = {J. Alloys Compd.},
year = {2017},
volume = {726},
pages = {978--988},
url = {https://linkinghub.elsevier.com/retrieve/pii/S092583881732772X},
doi = {10.1016/j.jallcom.2017.08.044}
}
|
| Troyanchuk I, Tereshko N, Silibin M, Gavrilov S, Nekludov K, Sikolenko V, Schorr S and Szymczak H (2017), "Magnetic ordering in manganites doped by Ti and Al", Ceram. Int.. Vol. 43(1), pp. 187-191. |
| Abstract: Neutron powder diffraction (NPD) and magnetization measurements have been performed for the La0.7Sr0.3Mn0.7Ti0.3−xAlxO3 (0≤x≤0.15) stoichiometric compounds. Increase of the Al3+ content enlarges the fraction of Mn4+ ions from 0% for the sample with x=0 up to around 20% for x=0.15 one. The compound without Al content undergoes a structural transition from rhombohedral phase to orbitally disordered orthorhombic one below room temperature whereas crystal structure of the compounds with x=0.1 and 0.15 remain to have rhombohedral one down to 2 K. The structural transition occurs well above the magnetic transition temperature. The substitution of Ti4+ by Al3+ ions is accompanied by a gradual increase in the bond angle Mn–O–Mn and Mn–O bond length thus strengthening the covalent component of the related chemical bonds. All these compounds are insulators and have ferromagnetic components. Magnetic moments calculated per manganese ion based on NPD data obtained at 2 K are found to change from 1.3 µB for x=0 compound up to 1.7 µB for x=0.1 and 0.15 ones. It is suggested that ferromagnetism is predominantly caused by superexchange interactions Mn3+–O–Mn3+ and Mn3+–O–Mn4+ whereas fluctuations in the bond angles and distances frustrate magnetic interactions. It is assumed that increase of covalency within the chemical bonds Mn–O slightly enforces ferromagnetic interactions. |
BibTeX:
@article{Troyanchuk2017a,
author = {Troyanchuk, I.O. and Tereshko, N.V. and Silibin, M.V. and Gavrilov, S.A. and Nekludov, K.N. and Sikolenko, V. and Schorr, S. and Szymczak, H.},
title = {Magnetic ordering in manganites doped by Ti and Al},
journal = {Ceram. Int.},
year = {2017},
volume = {43},
number = {1},
pages = {187--191},
doi = {10.1016/j.ceramint.2016.09.132}
}
|
| Troyanchuk IO, Bushinsky MV, Tereshko NV, Fedotova VV and Partyka J (2017), "Crystal structure and chemical characterization of La07Sr03Mn07Ti03-xAlxO3 (0≤ x ≤ 0.15) compounds", In Acta Phys. Pol. A., Aug, 2017. Vol. 132(2), pp. 240-244. |
| Abstract: Neutron powder diffraction and magnetization measurements have been performed for La0:7Sr0:3Mn0:7Ti0:3-xAlxO3 (0 ≤ x ≤ 0:15) stoichiometric compounds. Increase of the Al3+ content enlarges the Mn4+ ions fraction from 0% (x = 0) up to around 20% (x = 0:15). The x = 0 composition around 150 K exhibits a structural transition from the rhombohedral phase to the orthorhombic one whereas the crystal structure of the compounds with x = 0:1 and 0.15 remains to be rhombohedral down to 2 K. The substitution of Ti4+ by Al3+ ions is accompanied by a gradual increase in the bond angle Mn-O-Mn and decrease in the Mn-O bond length which lead to enhancement of the covalent component of the chemical bond. All these compounds exhibit ferromagnetic components below 100 K. Magnetic moments estimated per manganese from the neutron powder diffraction data are found to be around 1:3 μB (x = 0) and 1:7 μB (x = 0:1 and 0.15) at 2 K. It is suggested that ferromagnetism is originated predominantly from the Mn3+-O-Mn3+ and Mn3+-O-Mn4+ superexchange interactions whereas bond angles fluctuation leads to magnetic frustrations. Enhancement of covalence slightly increases ferromagnetism. |
BibTeX:
@inproceedings{Troyanchuk2017,
author = {Troyanchuk, I. O. and Bushinsky, M. V. and Tereshko, N. V. and Fedotova, V. V. and Partyka, J.},
title = {Crystal structure and chemical characterization of La0:7Sr0:3Mn0:7Ti0:3-xAlxO3 (0≤ x ≤ 0.15) compounds},
booktitle = {Acta Phys. Pol. A},
year = {2017},
volume = {132},
number = {2},
pages = {240--244},
url = {http://przyrbwn.icm.edu.pl/APP/PDF/132/app132z2p10.pdf},
doi = {10.12693/APhysPolA.132.240}
}
|
| Vaney JB, Delaizir G, Wiendlocha B, Tobola J, Alleno E, Piarristeguy A, Gonçalves AP, Gendarme C, Malaman B, Dauscher A, Candolfi C and Lenoir B (2017), "Effect of Isovalent Substitution on the Electronic Structure and Thermoelectric Properties of the Solid Solution α-As2Te3-xSex (0 ≤ x ≤ 1.5)", Inorg. Chem., Feb, 2017. Vol. 56(4), pp. 2248-2257. |
| Abstract: We report on the influence of Se substitution on the electronic band structure and thermoelectric properties (5-523 K) of the solid solution α-As2Te3-xSex (0 ≤ x ≤ 1.5). All of the polycrystalline compounds α-As2Te3-xSex crystallize isostructurally in the monoclinic space group C2/m (No. 12, Z = 4). Regardless of the Se content, chemical analyses performed by scanning electron microscopy and electron probe microanalysis indicate a good chemical homogeneity, with only minute amounts of secondary phases for some compositions. In agreement with electronic band structure calculations, neutron powder diffraction suggests that Se does not randomly substitute for Te but exhibits a site preference. These theoretical calculations further predict a monotonic increase in the band gap energy with the Se content, which is confirmed experimentally by absorption spectroscopy measurements. Increasing x up to x = 1.5 leaves unchanged both the p-type character and semiconducting nature of α-As2Te3. The electrical resistivity and thermopower gradually increase with x as a result of the progressive increase in the band gap energy. Despite the fact that α-As2Te3 exhibits very low lattice thermal conductivity κL, the substitution of Se for Te further lowers κL to 0.35 W m-1 K-1 at 300 K. The compositional dependence of the lattice thermal conductivity closely follows classical models of phonon alloy scattering, indicating that this decrease is due to enhanced point-defect scattering. |
BibTeX:
@article{Vaney2017,
author = {Vaney, Jean Baptiste and Delaizir, Gaëlle and Wiendlocha, Bartlomiej and Tobola, Janusz and Alleno, Eric and Piarristeguy, Andrea and Gonçalves, Antonio Pereira and Gendarme, Christine and Malaman, Bernard and Dauscher, Anne and Candolfi, Christophe and Lenoir, Bertrand},
title = {Effect of Isovalent Substitution on the Electronic Structure and Thermoelectric Properties of the Solid Solution α-As2Te3-xSex (0 ≤ x ≤ 1.5)},
journal = {Inorg. Chem.},
year = {2017},
volume = {56},
number = {4},
pages = {2248--2257},
url = {https://pubs.acs.org/doi/10.1021/acs.inorgchem.6b02930},
doi = {10.1021/acs.inorgchem.6b02930}
}
|
| Woźnica N, Hawełek Ł, Duber S, Fischer H, Honkimäki V, Pawlyta M, Bulou A and Burian A (2017), "The atomic scale structure of saccharose-based carbons", Philos. Mag.. Vol. 97(20), pp. 1675-1697. |
| Abstract: Activated carbons (ACs) have a wide range of applications, in which the largely expanded specific surface plays a major role. The question of their structure came back to the limelight with the discovery of nanotubes fullerenes, which suggested that curved surfaces may be present in their structure and which incorporates well into the ideas of ACs porous structure. The source of those curved surfaces is atomic defects present inside the in-plane graphitic honeycomb lattice. Such defects have a crucial influence on the macroscopic morphology as well as physical properties of the material. The activated carbon (AC) in this work was derived from carbonised saccharose by activation with NaOH. Both materials–before and after activation were investigated. The main methods used in this study are wide angle neutron scattering and wide angle X-ray scattering combined with computer simulations. Confirmation of the proposed structures was sought with high-resolution transmission electron microscopy and Raman scattering. In this case, the use of classical crystallography to interpret experimental data was impossible due to the lack of periodic three-dimensional symmetry. Due to this fact, the data was analysed both in real and reciprocal space in the form of a pair correlation function and a structure factor. The experimental data were compared with calculated atomistic models. As a validation, the discrepancy factor between the theoretically and experimentally obtained functions was used. The presented innovative approach can be applied to different carbon materials with varying degrees of disorder. |
BibTeX:
@article{Woznica2017,
author = {Woźnica, N. and Hawełek, Ł. and Duber, S. and Fischer, H.E. and Honkimäki, V. and Pawlyta, M. and Bulou, A. and Burian, A.},
title = {The atomic scale structure of saccharose-based carbons},
journal = {Philos. Mag.},
year = {2017},
volume = {97},
number = {20},
pages = {1675--1697},
doi = {10.1080/14786435.2017.1313465}
}
|
| Zajdel P, Gagor A, Pajerowski DM, Ptak M and Szlawska M (2017), "Suppression of the commensurate magnetic phase in nanosized hübnerite MnW O4", Phys. Rev. B., May, 2017. Vol. 95(17), pp. 174427. |
| Abstract: Magnetic structures of nanosized (20 to 70 nm) powders of MnWO4 and MnWO4:Mo were studied using neutron powder diffraction (NPD). Sizes and shapes of the crystallites calculated from anisotropic peak broadening of diffraction peaks were found to be orthogonal parallelepipedlike with the longest edge along the c axis and the shortest along the b axis. SQUID measurements indicate the presence of two magnetic transitions around 8 and 12 K. Rietveld refinement of the NPD data below the magnetic transition was consistent with the presence of an incommensurate spiral-like (ac-AF2) phase. A commensurate phase AF1 was not observed down to 2.5 K for all of the samples. |
BibTeX:
@article{Zajdel2017,
author = {Zajdel, P. and Gagor, A. and Pajerowski, D. M. and Ptak, M. and Szlawska, M.},
title = {Suppression of the commensurate magnetic phase in nanosized hübnerite MnW O4},
journal = {Phys. Rev. B},
year = {2017},
volume = {95},
number = {17},
pages = {174427},
url = {http://link.aps.org/doi/10.1103/PhysRevB.95.174427},
doi = {10.1103/PhysRevB.95.174427}
}
|
| Zajdel P, Li WY, Van Beek W, Lappas A, Ziółkowska A, Jaskiewicz S, Stock C and Green MA (2017), "Structure and magnetism in the bond-frustrated spinel ZnCr2Se4", Phys. Rev. B., Apr, 2017. Vol. 95(13), pp. 134401. |
| Abstract: The crystal and magnetic structures of stoichiometric ZnCr2Se4 have been investigated using synchrotron x-ray and neutron powder diffraction, muon spin relaxation (μSR), and inelastic neutron scattering. Synchrotron x-ray diffraction shows a spin-lattice distortion from the cubic Fd3m spinel to a tetragonal I41/amd lattice below TN=21K, where powder neutron diffraction confirms the formation of a helical magnetic structure with magnetic moment of 3.04(3)μB at 1.5 K, close to that expected for high-spin Cr3+. μSR measurements show prominent local spin correlations that are established at temperatures considerably higher (<100K) than the onset of long-range magnetic order. The stretched exponential nature of the relaxation in the local spin-correlation regime suggests a wide distribution of depolarizing fields. Below TN, unusually fast (>100μs-1) muon relaxation rates are suggestive of rapid site hopping of the muons in static field. Inelastic neutron scattering measurements show a gapless mode at an incommensurate propagation vector of k=[000.4648(2)] in the low-temperature magnetic ordered phase that extends to 0.8 meV. The dispersion is modeled by a two-parameter Hamiltonian, containing ferromagnetic nearest-neighbor and antiferromagnetic next-nearest-neighbor interactions with a Jnnn/Jnn=-0.337. |
BibTeX:
@article{Zajdel2017a,
author = {Zajdel, P. and Li, W. Y. and Van Beek, W. and Lappas, A. and Ziolkowska, A. and Jaskiewicz, S. and Stock, C. and Green, M. A.},
title = {Structure and magnetism in the bond-frustrated spinel ZnCr2Se4},
journal = {Phys. Rev. B},
year = {2017},
volume = {95},
number = {13},
pages = {134401},
url = {http://link.aps.org/doi/10.1103/PhysRevB.95.134401},
doi = {10.1103/PhysRevB.95.134401}
}
|
| Zhao Y, Le Joncour L, Baczmański A, François M, Wronski S, Panicaud B, Gadalinska E, Braham C, Buslaps T and Paradowska A (2017), "Elastoplastic deformation and damage process in duplex steel studied using synchrotron and neutron diffraction", In Mater. Sci. Forum. Vol. 905 MSF, pp. 9-16. |
| Abstract: In the present work, the mechanical behavior of phases in duplex steel during tensile test was studied. Special interest was taken in the analysis of damage process just before failure. In this aim two diffraction methods: in-situ time of flight neutron diffraction and X-ray synchrotron diffraction were applied. Using diffraction data, the slip mechanism on crystallographic planes during plastic deformation was investigated. In the case of aged UR45N steel, it was found that significant softening caused by damage process was initiated in the ferritic phase. The lattice strains measured in situ by two above mentioned diffraction methods were compared with prediction of the self-consistent model. |
BibTeX:
@book{Zhao2017,
author = {Zhao, Y. and Le Joncour, L. and Baczmanski, A. and François, M. and Wronski, S. and Panicaud, B. and Gadalinska, E. and Braham, C. and Buslaps, T. and Paradowska, A.},
title = {Elastoplastic deformation and damage process in duplex steel studied using synchrotron and neutron diffraction},
booktitle = {Mater. Sci. Forum},
year = {2017},
volume = {905 MSF},
pages = {9--16},
doi = {10.4028/www.scientific.net/MSF.905.9}
}
|
| Baczmański A, Zhao Y, Gadalińska E, Le Joncour L, Wroński S, Braham C, Panicaud B, François M, Buslaps T and Soloducha K (2016), "Elastoplastic deformation and damage process in duplex stainless steels studied using synchrotron and neutron diffractions in comparison with a self-consistent model", Int. J. Plast., Jun, 2016. Vol. 81, pp. 102-122. |
| Abstract: In situ time of flight neutron diffraction and X-ray synchrotron diffraction methods were applied to measure lattice strains in duplex steels during a tensile test. The experimental results were used to study slips on crystallographic planes and the mechanical effects of damage occurring during plastic deformation. For this purpose the prediction of an elastoplastic self-consistent model was compared with the experimental data. The used methodology allowed to determine the elastic limits and parameters describing work hardening in both phases of studied polycrystalline materials. In the second part of this work the developed elastoplastic model was applied to study damage occurring in the ferritic phase. The theoretical results showed a significant reduction of stresses localized in the damaged phase (ferrite) and confirmed the evolution of the lattice strains measured in the ferritic and austenitic phases. |
BibTeX:
@article{Baczmanski2016,
author = {Baczmański, A. and Zhao, Y. and Gadalińska, E. and Le Joncour, L. and Wroński, S. and Braham, C. and Panicaud, B. and François, M. and Buslaps, T. and Soloducha, K.},
title = {Elastoplastic deformation and damage process in duplex stainless steels studied using synchrotron and neutron diffractions in comparison with a self-consistent model},
journal = {Int. J. Plast.},
year = {2016},
volume = {81},
pages = {102--122},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0749641916300092},
doi = {10.1016/j.ijplas.2016.01.018}
}
|
| Baran S, Dyakonov V, Hoser A, Penc B, Zarzycki A and Szytuła A (2016), "Magnetic properties of the nanocrystalline DyMnO3", Phase Transitions., Apr, 2016. Vol. 89(4), pp. 319-327. |
| Abstract: We report on the X-ray and neutron diffraction and magnetic measurements of the nanosamples of DyMnO3 annealed at temperatures of 800 °C, 850 °C and 900 °C. The diffraction data indicate that all the samples crystallize in an orthorhombic crystal structure (space group Pnma). The crystal structure parameters change slightly with preparation. All the samples are antiferromagnets at low temperatures. The Mn magnetic moments order near 40 K, while those of Dy below 8.4 K. The macroscopic magnetic and neutron diffraction data indicate a small difference of properties between the DyMnO3 samples synthesized at different temperatures. The observed broadening of magnetic peaks connected with the Dy sublattice suggests a cluster-like character of magnetic ordering. |
BibTeX:
@article{Baran2016,
author = {Baran, Stanisław and Dyakonov, Vladimir and Hoser, Andreas and Penc, Bogusław and Zarzycki, Arkadiusz and Szytuła, Andrzej},
title = {Magnetic properties of the nanocrystalline DyMnO 3},
journal = {Phase Transitions},
year = {2016},
volume = {89},
number = {4},
pages = {319--327},
url = {http://www.tandfonline.com/doi/full/10.1080/01411594.2015.1131281},
doi = {10.1080/01411594.2015.1131281}
}
|
| Baran S, Hoser A, Penc B and Szytuła A (2016), "Size Effects in Antiferromagnetic NiO Nanoparticles", Acta Phys. Pol. A., Jan, 2016. Vol. 129(1), pp. 35-39. |
| Abstract: X-ray and neutron diffraction as well as magnetometric methods were used in order to investigate crystal and magnetic structure together with magnetic properties of nickel oxide NiO obtained from thermal decomposition of Ni(OH)2. It has been found that crystal unit cell volume and crystal unit cell deformation parameter decrease with increasing decomposition temperature Td while grain size increases. The results of magnetization, magnetic susceptibility and neutron diffraction measurements reveal a formation of antiferromagnetic order with uncompensated magnetic moment below the Néel temperature. Magnetization together with coercive field decreases with increasing Td. The neutron diffractogram of sample obtained at 240 °C indicates broadening of both the peaks of nuclear and magnetic origin. The magnetic ordering may be described by a propagation vector k = [1/2,1/2,1/2]. |
BibTeX:
@article{Baran2016a,
author = {Baran, S. and Hoser, A. and Penc, B. and Szytuła, A.},
title = {Size Effects in Antiferromagnetic NiO Nanoparticles},
journal = {Acta Phys. Pol. A},
year = {2016},
volume = {129},
number = {1},
pages = {35--39},
url = {http://przyrbwn.icm.edu.pl/APP/PDF/129/a129z1p07.pdf},
doi = {10.12693/APhysPolA.129.35}
}
|
| Baran S, Szytuła A, Kaczorowski D and Damay F (2016), "Complex magnetic ordering in Tm3Cu4Si4", J. Alloys Compd., Dec, 2016. Vol. 688, pp. 577-584. |
| Abstract: Tm3Cu4Si4crystalizes in the orthorhombic Gd3Cu4Ge4-type crystal structure with trivalent Tm atoms occupying 2(d) and 4(e) Wyckoff sites. Neutron diffraction data shows that at 1.7 K the Tm magnetic moments form a commensurate magnetic structure defined by the propagation vectors k→2d=[0,12,0] and k→4e=[14,0,1] for the 2(d) and 4(e) sites, respectively. With increasing temperature, the magnetic order in the 4(e) sublattice undergoes near 2.5 K an order-order transition into an incommensurate magnetic structure and then disappears at 2.9 K. Similar changes in the magnetic structure occur in the 2(d) sublattice at 3.3 and 3.8 K, respectively. |
BibTeX:
@article{Baran2016c,
author = {Baran, S. and Szytuła, A. and Kaczorowski, D. and Damay, F.},
title = {Complex magnetic ordering in Tm3Cu4Si4},
journal = {J. Alloys Compd.},
year = {2016},
volume = {688},
pages = {577--584},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838816322769},
doi = {10.1016/j.jallcom.2016.07.241}
}
|
| Baran S, Szytuła A, Kaczorowski D and Damay F (2016), "Magnetic structures in TmPdIn and TmAgSn", J. Alloys Compd.. Vol. 662, pp. 11-15. |
| Abstract: Low temperature antiferromagnetic structures of TmPdIn and TmAgSn have been derived from powder neutron diffraction data. The magnetic structure of TmPdIn is a commensurate one and related to a propagation vector k→=[13,13,12] while the incommensurate sine-modulated structure of TmAgSn is connected with k→=[kx,-kx,0] where kx = 0.1314(2). The thulium magnetic moments are constrained within the basal plane and show 'triangular' arrangement. Validity of obtained magnetic structures is discussed on the basis of symmetry analysis. |
BibTeX:
@article{Baran2016b,
author = {Baran, S. and Szytuła, A. and Kaczorowski, D. and Damay, F.},
title = {Magnetic structures in TmPdIn and TmAgSn},
journal = {J. Alloys Compd.},
year = {2016},
volume = {662},
pages = {11--15},
doi = {10.1016/j.jallcom.2015.11.200}
}
|
| Benton O, Sikora O and Shannon N (2016), "Classical and quantum theories of proton disorder in hexagonal water ice", Phys. Rev. B., Mar, 2016. Vol. 93(12), pp. 125143. |
| Abstract: It has been known since the pioneering work of Bernal, Fowler, and Pauling that common, hexagonal (Ih) water ice is the archetype of a frustrated material: a proton-bonded network in which protons satisfy strong local constraints (the "ice rules") but do not order. While this proton disorder is well established, there is now a growing body of evidence that quantum effects may also have a role to play in the physics of ice at low temperatures. In this paper, we use a combination of numerical and analytic techniques to explore the nature of proton correlations in both classical and quantum models of ice Ih. In the case of classical ice Ih, we find that the ice rules have two, distinct, consequences for scattering experiments: singular "pinch points," reflecting a zero-divergence condition on the uniform polarization of the crystal, and broad, asymmetric features, coming from its staggered polarization. In the case of the quantum model, we find that the collective quantum tunneling of groups of protons can convert states obeying the ice rules into a quantum liquid, whose excitations are birefringent, emergent photons. We make explicit predictions for scattering experiments on both classical and quantum ice Ih, and show how the quantum theory can explain the "wings" of incoherent inelastic scattering observed in recent neutron scattering experiments [Bove, Phys. Rev. Lett. 103, 165901 (2009)PRLTAO0031-900710.1103/PhysRevLett.103.165901]. These results raise the intriguing possibility that the protons in ice Ih could form a quantum liquid at low temperatures, in which protons are not merely disordered, but continually fluctuate between different configurations obeying the ice rules. |
BibTeX:
@article{Benton2016,
author = {Benton, Owen and Sikora, Olga and Shannon, Nic},
title = {Classical and quantum theories of proton disorder in hexagonal water ice},
journal = {Phys. Rev. B},
year = {2016},
volume = {93},
number = {12},
pages = {125143},
url = {https://link.aps.org/doi/10.1103/PhysRevB.93.125143},
doi = {10.1103/PhysRevB.93.125143}
}
|
| Cieślak J, Toboła J and Dubiel S (2016), "Site occupancies in sigma-phase Fe–Cr–X (X = Co, Ni) alloys: Calculations versus experiment", Comput. Mater. Sci., Sep, 2016. Vol. 122, pp. 229-239. |
| Abstract: Ternary sigma-phase Fe-Cr-X (X = Co, Ni) alloys were studied theoretically (electronic structure calculations, Gibbs free energy analysis) and experimentally (X-ray diffraction, neutron diffraction, Mössbauer spectroscopy) in order to determine sublattice site occupancies by alloying elements. In general, good agreement between the predictions and experimental data was achieved. The obtained results agree reasonably well with expectations i.e. both Co and Ni atoms substitute for Fe atoms which predominantly occupy the sites A and D. |
BibTeX:
@article{Cieslak2016,
author = {Cieślak, J. and Tobola, J. and Dubiel, S.M.},
title = {Site occupancies in sigma-phase Fe–Cr–X (X = Co, Ni) alloys: Calculations versus experiment},
journal = {Comput. Mater. Sci.},
year = {2016},
volume = {122},
pages = {229--239},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0927025616302221},
doi = {10.1016/j.commatsci.2016.05.008}
}
|
| Druzbicki K, Pinna R, Rudić S, Jura M, Gorini G and Fernandez-Alonso F (2016), "Unexpected Cation Dynamics in the Low-Temperature Phase of Methylammonium Lead Iodide: The Need for Improved Models", J. Phys. Chem. Lett.. Vol. 7(22), pp. 4701-4709. |
| Abstract: High-resolution inelastic neutron scattering and extensive first-principles calculations have been used to explore the low-temperature phase of the hybrid solar-cell material methylammonium lead iodide up to the well-known phase transition to the tetragonal phase at ca. 160 K. Contrary to original expectation, we find that the Pnma structure for this phase can only provide a qualitative description of the geometry and underlying motions of the organic cation. A substantial lowering of the local symmetry inside the perovskite cage leads to an improved atomistic model that can account for all available spectroscopic and thermodynamic data, both at low temperatures and in the vicinity of the aforementioned phase transition. Further and detailed analysis of the first-principles calculations reveals that large-amplitude distortions of the inorganic framework are driven by both zero-point-energy fluctuations and thermally activated cation motions. These effects are significant down to liquid-helium temperatures. For this important class of technological materials, this work brings to the fore the pressing need to bridge the gap between the long-range order seen by crystallographic methods and the local environment around the organic cation probed by neutron spectroscopy. |
BibTeX:
@article{Druzbicki2016,
author = {Druzbicki, K. and Pinna, R.S. and Rudić, S. and Jura, M. and Gorini, G. and Fernandez-Alonso, F.},
title = {Unexpected Cation Dynamics in the Low-Temperature Phase of Methylammonium Lead Iodide: The Need for Improved Models},
journal = {J. Phys. Chem. Lett.},
year = {2016},
volume = {7},
number = {22},
pages = {4701--4709},
doi = {10.1021/acs.jpclett.6b01822}
}
|
| Ewings RA, Perring TG, Sikora O, Abernathy DL, Tomioka Y and Tokura Y (2016), "Spin excitations used to probe the nature of exchange coupling in the magnetically ordered ground state of Pr0.5Ca0.5MnO3", Phys. Rev. B., Jul, 2016. Vol. 94(1), pp. 014405. |
| Abstract: We have used time-of-flight inelastic neutron scattering to measure the spin wave spectrum of the canonical half-doped manganite Pr0.5Ca0.5MnO3 in its magnetic and orbitally ordered phase. The data, which cover multiple Brillouin zones and the entire energy range of the excitations, are compared with several different models that are all consistent with CE-type magnetic order, but arise through different exchange coupling schemes. The Goodenough model, i.e., an ordered state comprising strong nearest-neighbor ferromagnetic interactions along zigzag chains with antiferromagnetic interchain coupling, provides the best description of the data, provided that further neighbor interactions along the chains are included. We are able to rule out a coupling scheme involving formation of strongly bound ferromagnetic dimers, i.e., Zener polarons, on the basis of gross features of the observed spin wave spectrum. A model with weaker dimerization reproduces the observed dispersion but can be ruled out on the basis of discrepancies between the calculated and observed structure factors at certain positions in reciprocal space. Adding further neighbor interactions results in almost no dimerization, i.e., recovery of the Goodenough model. These results are consistent with theoretical analysis of the degenerate double exchange model for half-doping, and provide a recipe for how to interpret future measurements away from half-doping, where degenerate double exchange models predict more complex ground states. |
BibTeX:
@article{Ewings2016,
author = {Ewings, R. A. and Perring, T. G. and Sikora, O. and Abernathy, D. L. and Tomioka, Y. and Tokura, Y.},
title = {Spin excitations used to probe the nature of exchange coupling in the magnetically ordered ground state of Pr0.5Ca0.5MnO3},
journal = {Phys. Rev. B},
year = {2016},
volume = {94},
number = {1},
pages = {014405},
url = {https://link.aps.org/doi/10.1103/PhysRevB.94.014405},
doi = {10.1103/PhysRevB.94.014405}
}
|
| Fidrysiak M (2016), "Origin of longitudinal spin excitations in iron-pnictide parent compounds", Eur. Phys. J. B., Feb, 2016. Vol. 89(2), pp. 41. |
| Abstract: We investigate longitudinal spin excitations (LSEs) as a probe of microscopic origin ofmagnetic ordering in parent pnictides BaFe2As2 and NaFeAs. Currently adopted interpretation ofLSEs as bottom of particle-hole continuum points unambiguously toward itinerant-electronmagnetism, but is difficult to reconcile with available optical measurements. We study thepossibility that the LSEs originate from multi-magnon processes which are notenergetically constrained by optical spectroscopy and do not sharply distinguish betweenlocal-moment and itinerant scenarios. Two mechanisms, capable of enhancing multi-magnoncontinuum to the level indicated by neutron scattering experiments, are proposed. Thefirst emphasizes itinerant electrons and is based on electronic transitions betweenmagnetically split bands, while the other relies on purely spin fluctuations close to amagnetic quantum phase transition. Electronic excitations enhance multi-magnoncontribution to LSEs for small Fermi surface taking part in the SDW instability, but areinsufficient to account for measured intensities. The correct order of LSEs, on the otherhand, can be reproduced by the spin fluctuation mechanism for a reasonable set ofparameters. |
BibTeX:
@article{Fidrysiak2016,
author = {Fidrysiak, Maciej},
title = {Origin of longitudinal spin excitations in iron-pnictide parent compounds},
journal = {Eur. Phys. J. B},
year = {2016},
volume = {89},
number = {2},
pages = {41},
url = {http://link.springer.com/10.1140/epjb/e2016-60588-6},
doi = {10.1140/epjb/e2016-60588-6}
}
|
| Hawelek L, Wlodarczyk P, Hudecki A, Lis M, Zackiewicz P, Jurkiewicz K, Szade J, Kubacki J, Balin K, Fischer H, Kolano-Burian A and Burian A (2016), "The atomic scale structure of glass-like carbon obtained from fullerene extract via spark plasma sintering", Carbon N. Y.. Vol. 110, pp. 172-179. |
| Abstract: The spark plasma sintering technique was successfully used to transform fullerene extract into glass-like carbon. The sintered sample was characterized via thermogravimetry, scanning electron microscopy, X-ray photoelectron spectroscopy, the X-ray and neutron diffraction. To reconstruct the atomic scale structure the diffraction results were combined with computer simulations. The comparative analysis was performed in the form of the structure factor and the pair correlation function in the reciprocal and direct space. In the first approach the two different concepts of graphite-based models have been verified. For such constructed models the pair correlation functions maxima positions indicate the strong differences in comparison with the experimental data. In the second approach the proposed models were constructed successively on the icosahedral from C960 up to C3840 fullerenes fragments. The final model consists of triple layer fullerene C3840-like fragments in which the isolated pentagon presence guaranties the stronger curvature. The calculated pair correlation function fits the experimental data well and therefore proves that the atomic structure of sintered glass-like materials originated from C60/C70 fullerene extract consists of defected fullerene C3840-like fragments. The curvature was assured by isolated pentagon, but the disorder of surrounded hexagonal lattice was modeled and properly reconstructed by the Stone-Thrower-Wales topological defects. |
BibTeX:
@article{Hawelek2016,
author = {Hawelek, L. and Wlodarczyk, P. and Hudecki, A. and Lis, M. and Zackiewicz, P. and Jurkiewicz, K. and Szade, J. and Kubacki, J. and Balin, K. and Fischer, H.E. and Kolano-Burian, A. and Burian, A.},
title = {The atomic scale structure of glass-like carbon obtained from fullerene extract via spark plasma sintering},
journal = {Carbon N. Y.},
year = {2016},
volume = {110},
pages = {172--179},
doi = {10.1016/j.carbon.2016.09.017}
}
|
| Hetmańczyk J and Hetmańczyk S (2016), "Raman light scattering, infrared absorption and neutron scattering studies of the phase transition and reorientational dynamics of H2O ligands and ClO4– anions in [Ca(H2O)4](ClO4)2", Vib. Spectrosc., Mar, 2016. Vol. 83, pp. 26-35. |
| Abstract: Vibrational-reorientational dynamics of H2O ligands and ClO4- anions in the high-, intermediate- and low-temperature phases of [Ca(H2O)4](ClO4)2, detected previously by differential scanning calorimetry (DSC) method, were investigated. The following experimental methods were applied to achieve the goal: middle-infrared (FT-MIR), Raman spectroscopy (RS) and inelastic incoherent neutron scattering (IINS). FT-MIR and RS spectra versus temperature show distinct changes in full-width-at-half-maximum (FWHM) of some bands connected with vibrational modes of ClO4- and [Ca(H2O)4]2+ ions. It suggests that in the high temperature phase these ions (and also the ligands from complex cation) perform fast (picoseconds correlation time scale, which is characteristic for optical spectroscopy) stochastic reorientational motions, however in the lower temperatures the speed of these motions is slowed down. Moreover, the splitting of some bands accompanying the observed phase transitions. The comparison of the results obtained by these complementary methods was made. Additionally, IR, RS and IINS spectra were calculated by the DFT method and an excellent agreement with the experimental data was obtained using CASTEP plane-wave periodic boundary condition code. The bands were assigned based on analysis of the phonon eigenvectors obtained from CASTEP calculations. |
BibTeX:
@article{Hetmanczyk2016,
author = {Hetmańczyk, Joanna and Hetmańczyk, Sukasz},
title = {Raman light scattering, infrared absorption and neutron scattering studies of the phase transition and reorientational dynamics of H2O ligands and ClO4– anions in [Ca(H2O)4](ClO4)2},
journal = {Vib. Spectrosc.},
year = {2016},
volume = {83},
pages = {26--35},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0924203116300054},
doi = {10.1016/j.vibspec.2016.01.005}
}
|
| Hetmańczyk J, Hetmańczyk Ł, Migdał-Mikuli A and Mikuli E (2016), "Vibrational and reorientational dynamics, crystal structure and solid-solid phase transition studies in [Ca(H2O)6]Cl2 supported by theoretical (DFT) calculations", J. Raman Spectrosc.. Vol. 47(5), pp. 591-601. |
| Abstract: [Ca(H2O)6]Cl2 between 93 and 300 K possesses two solid phases. One phase transition (PT) of the first-order type at TCh = 218.0 K (on heating) and TCc = 208.0 K (on cooling) was determined by differential scanning calorimetry. Thermal hysteresis of this PT (10 K), as well as the heat flow anomaly sharpness, suggests that the detected PT is a first-order one. The entropy change value [ΔS ≈ 8.5 J mol-1 K-1 ≈ Rln(2.8)] associated with the observed PT suggests a moderate degree of molecular dynamical disorder of the high-temperature phase. The temperature dependencies of the full width at half maximum values of the infrared band are due to ρ(H2O)A2 mode (at 205 cm-1), and two Raman bands are arising from τ(H2O)E and τ(H2O)A1 modes (at ca. 410 and 682 cm-1, respectively), suggesting that the observed PT is associated with a sudden change of speed of the H2O reorientational motions. The estimated mean value of activation energy for the reorientation of the H2O ligands in the high-temperature phase is ca. 11.4 kJ mol-1 from Raman spectroscopy and 11.9 kJ mol-1 from infrared spectroscopy. X-ray single-crystal diffraction measurement and spectroscopic studies (infrared, Raman and inelastic neutron scattering) also confirm that [Ca(H2O)6]Cl2 includes two sets of differently bonded H2O molecules. Ab initio calculations of the complete unit cell of one molecule of calcium chloride with a different number of water molecules (2, 4 and 6) have also been carried out. A comparison of Fourier Transform Infrared (FT-IR), Fourier Transform Raman Scattering (FT-RS) and inelastic neutron scattering spectroscopies results with periodic density functional theory calculations was used to provide a complete assignment of the vibrational spectra of [Ca(H2O)6]Cl2. |
BibTeX:
@article{Hetmanczyk2016a,
author = {Hetmańczyk, Joanna and Hetmańczyk, Łukasz and Migdał-Mikuli, Anna and Mikuli, Edward},
title = {Vibrational and reorientational dynamics, crystal structure and solid-solid phase transition studies in [Ca(H2O)6]Cl2 supported by theoretical (DFT) calculations},
journal = {J. Raman Spectrosc.},
year = {2016},
volume = {47},
number = {5},
pages = {591--601},
doi = {10.1002/jrs.4863}
}
|
| Hetmańczyk Ł and Hetmańczyk J (2016), "Phase transition and dynamics of NH3 ligands in [Zn(NH3)4](ReO4)2", Vib. Spectrosc.. Vol. 86, pp. 40-49. |
| Abstract: One phase transition in [Zn(NH3)4](ReO4)2 at Tc = 393.5 K (on heating) and 392.0 K (on cooling) was found. Thermal stability of this compound was investigated by thermal analysis methods. It decomposes in three main stages. The first two are connected with deamination process, whereas Re2O7 evaporates in the last step. The activation energy for NH3 loss processes was determined from thermogravimetric (TG) measurements. The vibrational and reorientational dynamics of NH3 ligands in the low-temperature phase was probed by various complementary techniques. It was found that at temperatures close to 150 K, N-HO hydrogen bond is formed. Temperature-dependent band shape analysis of properly chosen infrared (IR) band was performed, whose results showed that activation energy for NH3 reorientational motion (<300 K) is rather small and is approximately equal to 2 kJ mol-1. Neutron and X-ray powder diffraction patterns did not reveal any drastic change in the crystal structure in a wide temperature range. |
BibTeX:
@article{Hetmanczyk2016b,
author = {Hetmańczyk, Łukasz and Hetmańczyk, Joanna},
title = {Phase transition and dynamics of NH3 ligands in [Zn(NH3)4](ReO4)2},
journal = {Vib. Spectrosc.},
year = {2016},
volume = {86},
pages = {40--49},
doi = {10.1016/j.vibspec.2016.06.001}
}
|
| Jin WT, Xiao Y, Bukowski Z, Su Y, Nandi S, Sazonov AP, Meven M, Zaharko O, Demirdis S, Nemkovski K, Schmalzl K, Tran LM, Guguchia Z, Feng E, Fu Z and Brückel T (2016), "Phase diagram of Eu magnetic ordering in Sn-flux-grown Eu(Fe1-xCox)2As2 single crystals", Phys. Rev. B., Nov, 2016. Vol. 94(18), pp. 184513. |
| Abstract: The magnetic ground state of the Eu2+ moments in a series of Eu(Fe1-xCox)2As2 single crystals grown from the Sn flux has been investigated in detail by neutron diffraction measurements. Combined with the results from the macroscopic properties (resistivity, magnetic susceptibility and specific heat) measurements, a phase diagram describing how the Eu magnetic order evolves with Co doping in Eu(Fe1-xCox)2As2 is established. The ground-state magnetic structure of the Eu2+ spins is found to develop from the A-type antiferromagnetic (AFM) order in the parent compound, via the A-type canted AFM structure with some net ferromagnetic (FM) moment component along the crystallographic c direction at intermediate Co doping levels, finally to the pure FM order at relatively high Co doping levels. The ordering temperature of Eu declines linearly at first, reaches the minimum value of 16.5(2) K around x=0.100(4), and then reverses upwards with further Co doping. The doping-induced modification of the indirect Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between the Eu2+ moments, which is mediated by the conduction d electrons on the (Fe,Co)As layers, as well as the change of the strength of the direct interaction between the Eu2+ and Fe2+ moments, might be responsible for the change of the magnetic ground state and the ordering temperature of the Eu sublattice. In addition, for Eu(Fe1-xCox)2As2 single crystals with 0.10≤x≤0.18, strong ferromagnetism from the Eu sublattice is well developed in the superconducting state, where a spontaneous vortex state is expected to account for the compromise between the two competing phenomena. |
BibTeX:
@article{Jin2016,
author = {Jin, W. T. and Xiao, Y. and Bukowski, Z. and Su, Y. and Nandi, S. and Sazonov, A. P. and Meven, M. and Zaharko, O. and Demirdis, S. and Nemkovski, K. and Schmalzl, K. and Tran, Lan Maria and Guguchia, Z. and Feng, E. and Fu, Z. and Brückel, Th.},
title = {Phase diagram of Eu magnetic ordering in Sn-flux-grown Eu(Fe1-x Cox)2 As2 single crystals},
journal = {Phys. Rev. B},
year = {2016},
volume = {94},
number = {18},
pages = {184513},
url = {https://link.aps.org/doi/10.1103/PhysRevB.94.184513},
doi = {10.1103/PhysRevB.94.184513}
}
|
| Juszyńska-Gałązka E and Zając W (2016), "QENS study of molecular motions in partially deuterated liquid crystal 4BT", Phase Transitions. Vol. 89(4), pp. 411-418. |
| Abstract: Molecular rotational dynamic in the crystalline and smectic E phases of selectively deuterated (in the outer phenyl ring) 4-n-butyl-isothiocyanatobiphenyl was investigated by means of quasielastic neutron scattering. The 120° reorientation of the methyl group in the crystal phase could be identified at 125 K. Additionally, ring flips were seen at 200 K. The structure of crystal and smectic E phases was obtained by X-ray measurements and the data give the identification of type of solid phases. |
BibTeX:
@article{Juszynska-Galazka2016,
author = {Juszynska-Galazka, E. and Zajac, W.},
title = {QENS study of molecular motions in partially deuterated liquid crystal 4BT},
journal = {Phase Transitions},
year = {2016},
volume = {89},
number = {4},
pages = {411--418},
doi = {10.1080/01411594.2015.1114617}
}
|
| Kędzior M and Zawadzki J (2016), "Comparative study of soil moisture estimations from SMOS satellite mission, GLDAS database, and cosmic-ray neutrons measurements at COSMOS station in Eastern Poland", Geoderma. Vol. 283, pp. 21-31. |
| Abstract: The paper presents a detailed comparative study of three surface soil moisture datasets retrieved from Cosmic-Ray Soil Moisture Observing System (COSMOS) in situ neutron measurement, CATDS Soil Moisture Ocean Salinity (SMOS) satellite microwave observations, and modelled data of the Global Land Data Assimilation System (GLDAS). Subsurface datasets were also calculated from the in situ and satellite measurements by using an exponential filter and were compared with the GLDAS estimates. For these comparisons, the Triple Collocation (TC) method, Nash–Sutcliffe Efficiency (NSE) coefficients, trend charts, and scatterplots were used. The main goal of this work was to verify the concordance of cosmic-ray neutron measurements with low-resolution soil moisture data from the CATDS SMOS and GLDAS products. The second objective was to determine the possibility of obtaining comparable subsurface soil moisture products from the aforementioned soil moisture data source. The obtained results show that data from the COSMOS sensor, which assesses soil moisture in an area 600 m in diameter, agree reasonably well with the CATDS SMOS and GLDAS data having spatial resolution of about 25 km. These conclusions suggest that COSMOS Derlo measurements can be particularly useful for validation of low-resolution satellite soil moisture observations as well as modelled values. The results obtained by using the TC method also revealed satisfactory agreement among all studied surface soil moisture data. However, the performed analysis shows some preponderance of SMOS and COSMOS data over GLDAS products. Although GLDAS data show a noticeable smoothing effect, COSMOS and CATDS SMOS more effectively reveal temporal soil moisture changes. Thus, for some applications, the use of CATDS SMOS estimates rather than GLDAS products may be more appropriate. Results retrieved by using an exponential filter are significant and encouraging. In particular, subsurface soil moisture values calculated from CATDS SMOS show stronger correlation with COSMOS Derlo data than those of GLDAS. Furthermore, COSMOS Derlo data also respond more intensively to surface soil moisture changes. |
BibTeX:
@article{Kedzior2016,
author = {Kędzior, M. and Zawadzki, J.},
title = {Comparative study of soil moisture estimations from SMOS satellite mission, GLDAS database, and cosmic-ray neutrons measurements at COSMOS station in Eastern Poland},
journal = {Geoderma},
year = {2016},
volume = {283},
pages = {21--31},
doi = {10.1016/j.geoderma.2016.07.023}
}
|
| Kolesnikov AI, Podlesnyak A, Sadykov RA, Antonov VE, Kuzovnikov MA, Ehlers G and Granroth GE (2016), "Pressure effect on hydrogen tunneling and vibrational spectrum in α-Mn", Phys. Rev. B., Oct, 2016. Vol. 94(13), pp. 134301. |
| Abstract: The pressure effect on the tunneling mode and vibrational spectra of hydrogen in α-MnH0.07 has been studied by inelastic neutron scattering. Applying hydrostatic pressure of up to 30 kbar is shown to shift both the hydrogen optical modes and the tunneling peak to higher energies. First-principles calculations show that the potential for hydrogen in α-Mn becomes overall steeper with increasing pressure. At the same time, the barrier height and its extent in the direction of tunneling decrease and the calculations predict significant changes of the dynamics of hydrogen in α-Mn at 100 kbar, when the estimated tunneling splitting of the hydrogen ground state exceeds the barrier height. |
BibTeX:
@article{Kolesnikov2016,
author = {Kolesnikov, A. I. and Podlesnyak, A. and Sadykov, R. A. and Antonov, V. E. and Kuzovnikov, M. A. and Ehlers, G. and Granroth, G. E.},
title = {Pressure effect on hydrogen tunneling and vibrational spectrum in α -Mn},
journal = {Phys. Rev. B},
year = {2016},
volume = {94},
number = {13},
pages = {134301},
url = {https://link.aps.org/doi/10.1103/PhysRevB.94.134301},
doi = {10.1103/PhysRevB.94.134301}
}
|
| Kopeć M, Rozpedzik A, Łapok L, Geue T, Laschewsky A and Zapotoczny S (2016), "Stratified Micellar Multilayers - Toward Nanostructured Photoreactors", Chem. Mater.. Vol. 28(7), pp. 2219-2228. |
| Abstract: Polyelectrolyte multilayers (PEMs) with stratification of the internal structure were assembled from statistical amphiphilic copolyelectrolytes of opposite charges. These polyelectrolytes organize in aqueous solutions into micellar structures with fluoroalkyl and aromatic nanodomains, respectively, that were also preserved after deposition as thin films via layer-by-layer (LbL) electrostatic self-assembly. The unimolecular micelles, formed due to statistical compositions of amphiphilic polyelectrolytes used, were shown to suppress chain interdiffusion between adjacent layers in resulting micellar PEMs, as evidenced by spectroscopic ellipsometry, atomic force microscopy (AFM), and neutron reflectometry (NR) measurements. Additionally, hydrophobic cores of the micelles were used as hosts for photoactive molecules, namely, ferrocene and perfluorinated magnesium phthalocyanine. Stratified micellar multilayers were then deposited as hollow capsules using CaCO3 microparticles as templates. Photoinduced electron transfer (PET) between ferrocene and phthalocyanine solubilized in the polymer micelles was demonstrated to occur efficiently inside the stratified, polyelectrolyte walls of the capsules, due to the polarity gradient created by the incompatible aromatic and fluoroalkyl domains. The obtained results present a new approach to construct well-organized, self-assembled nanostructured materials for solar energy conversion. |
BibTeX:
@article{Kopec2016,
author = {Kopeć, M. and Rozpedzik, A. and Łapok, L. and Geue, T. and Laschewsky, A. and Zapotoczny, S.},
title = {Stratified Micellar Multilayers - Toward Nanostructured Photoreactors},
journal = {Chem. Mater.},
year = {2016},
volume = {28},
number = {7},
pages = {2219--2228},
doi = {10.1021/acs.chemmater.6b00161}
}
|
| Kudryavtsev YV, Perekos AO, Glavatskyy IN, Dubowik J and Skirta YB (2016), "Neutron diffraction study of Fe2MnGa heusler alloys", Metallofiz. i Noveishie Tekhnologii., Mar, 2016. Vol. 38(1), pp. 53-66. |
| Abstract: Effect of temperature and magnetic field on the structure and magnetic properties of Fe50.1Mn22.7Ga27.2 and Fe51.6Mn17.8Ga30.6 alloys is investigated in a temperature range 100 K < T < 580 K. by using elastic neutron diffraction (ND) and magnetometry. The degree of atomic order as well as magnetic moments localized at the Mn and Fe sites in the investigated Fe2MnGa alloys are experimentally evaluated using the ND data. Some disagreement between the experimental and calculated values of magnetic moments localized at the Mn and Fe sites can be explained by noticeable atomic disorder in the prepared Fe2MnGa alloys. If antiferromagnetic order really exists in L12-phase containing Fe50.1Mn22.7Ga27.2 alloy, this order has not a collinear character. |
BibTeX:
@article{Kudryavtsev2016,
author = {Kudryavtsev, Yu V. and Perekos, A. O. and Glavatskyy, I. N. and Dubowik, J. and Skirta, Yu B.},
title = {Neutron diffraction study of Fe2MnGa heusler alloys},
journal = {Metallofiz. i Noveishie Tekhnologii},
year = {2016},
volume = {38},
number = {1},
pages = {53--66},
url = {http://mfint.imp.kiev.ua/en/abstract/v38/i01/0053.html},
doi = {10.15407/mfint.38.01.0053}
}
|
| Kuna R, Adamiak S, Petit S, Baroni P, Gas K, Minikayev R, Szczerbakow A, Łazewski J and Szuszkiewiczb W (2016), "Hardening of (Pb,Cd)Te crystal lattice with an increasing CdTe content in the solid solution", Acta Phys. Pol. A. Vol. 130(5), pp. 1245-1247. |
| Abstract: Single crystals of the (Pb,Cd)Te solid solution with CdTe content up to 9% were grown by self-selecting vapour growth method and investigated by powder X-ray diffraction, inelastic neutron scattering, and nanoindentation measurements. The analysis of the linear part of the LA phonon dispersion, determined by the inelastic neutron scattering demonstrated an increase of the sound velocity (thus the hardening of the crystal lattice) with an increase of CdTe content in the solid solution. An important increase of microhardness value for (Pb,Cd)Te was directly confirmed by results of nanoindentation measurements performed for a few samples with various chemical composition. |
BibTeX:
@article{Kuna2016,
author = {Kuna, R. and Adamiak, S. and Petit, S. and Baroni, P. and Gas, K. and Minikayev, R. and Szczerbakow, A. and Łazewski, J. and Szuszkiewiczb, W.},
title = {Hardening of (Pb,Cd)Te crystal lattice with an increasing CdTe content in the solid solution},
journal = {Acta Phys. Pol. A},
year = {2016},
volume = {130},
number = {5},
pages = {1245--1247},
doi = {10.12693/APhysPolA.130.1245}
}
|
| Kuna R, Minikayev R, Trzyna M, Gas K, Bosak A, Szczerbakow A, Petit S, Łazewski J and Szuszkiewicz W (2016), "Inelastic X-ray scattering studies of phonon dispersion in PbTe and (Pb,Cd)Te solid solution", Acta Phys. Pol. A. Vol. 130(5), pp. 1251-1254. |
| Abstract: PbTe and its solid solution (Pb,Cd)Te containing 2% of CdTe and PbTe grown by self-selecting vapour growth technique were investigated by inelastic X-ray scattering using synchrotron radiation. The ID28 beamline at ESRF with the incident photon energy of 17794 eV and the energy resolution of 3 meV was applied for that purpose. The measurements were performed at room temperature along [001]-type high symmetry direction in the Brillouin zone. In spite of a very low energy of phonon branches they can be determined by inelastic X-ray scattering with a high accuracy. The transversal acoustic phonon dispersion obtained by inelastic X-ray scattering corresponds well to those resulting from inelastic neutron scattering measurements and ab initio calculations. Apart from expected structures corresponding to the bulk phonons an additional scattering related to the crystal surface properties was observed in the inelastic X-ray scattering spectra. The analysis performed with the use of secondary ion mass spectroscopy technique demonstrated a presence of a thin oxide layer at sample surfaces. |
BibTeX:
@article{Kuna2016a,
author = {Kuna, R. and Minikayev, R. and Trzyna, M. and Gas, K. and Bosak, A. and Szczerbakow, A. and Petit, S. and Łazewski, J. and Szuszkiewicz, W.},
title = {Inelastic X-ray scattering studies of phonon dispersion in PbTe and (Pb,Cd)Te solid solution},
journal = {Acta Phys. Pol. A},
year = {2016},
volume = {130},
number = {5},
pages = {1251--1254},
doi = {10.12693/APhysPolA.130.1251}
}
|
| Magiera J (2016), "An experimental study of the development of three-dimensional rail residual stress at various manufacturing stages", Civil-Comp Proc.. Vol. 110 |
| Abstract: This paper presents the results of a hybrid, experimental-numerical investigation of the three-dimensional rail residual stress in several rail samples. The main interest is to study the changing patterns of the rail residual stress as it accumulates on different portions of the rail manufacture process, to find their distributions and amplitudes that might be of importance for follow-up studies, both theoretical and experimental, devoted for example to a better understanding of rail manufacturing processes and their optimization or to a better modeling of the actual stress fields in rails mounted in track. The examinations included four samples: an air cooled rail, an air cooled and roller straightened rail, a head hardened rail and a head hardened and roller straightened rail. All experiments were performed on the US CFI 136RE rail, cut into transverse and oblique slices and scanned for stresses with a neutron diffraction (ND) technique. A dedicated numerical procedure was used for physically based enhancement of the raw two-dimensional data and then for reconstruction of the original and undisturbed by the sectioning three-dimensional stress fields. |
BibTeX:
@article{Magiera2016a,
author = {Magiera, J.},
title = {An experimental study of the development of three-dimensional rail residual stress at various manufacturing stages},
journal = {Civil-Comp Proc.},
year = {2016},
volume = {110},
doi = {10.4203/ccp.110.173}
}
|
| Magiera J (2016), "Experimental-numerical study of manufacture induced 3D rail residual stress", In Solid State Phenom.. Vol. 240, pp. 17-24. |
| Abstract: The purpose of this research was to investigate the changing patterns of the 3D rail residual stress as it accumulates on different portions of the rail manufacturing process. These patterns are of interest for manufacturers and railroad companies but also could serve as initial fields for various further numerical analyses of actual residual stress states in rails, wear and crack formation/development. Examined were four rail samples taken directly from manufacturing: 1. an air cooled rail; 2. an air cooled and roller straightened rail; 3. a head hardened rail; 4. a head hardened and roller straightened rail. An advanced experimental-numerical hybrid technique was developed and applied to perform all the required data reduction tasks. It comprises of an sectioning scheme called as the transverse/oblique slicing (T/O-S) technique and of a physically reasonable data reduction/smoothing procedure called as the global method (GM). Destructive experimental examinations were performed with the neutron diffraction method on thin rail slices at atomic reactor facility of US DOC, NIST Center for Neutron Research in Gaithersburg, MD. In the paper presented and discussed are results of the performed analyses. |
BibTeX:
@book{Magiera2016,
author = {Magiera, J.},
title = {Experimental-numerical study of manufacture induced 3D rail residual stress},
booktitle = {Solid State Phenom.},
year = {2016},
volume = {240},
pages = {17--24},
doi = {10.4028/www.scientific.net/SSP.240.17}
}
|
| Majerz I (2016), "Proton Transfer Influence on Geometry and Electron Density in Benzoic Acid-Pyridine Complexes", Helv. Chim. Acta. Vol. 99(4), pp. 286-295. |
| Abstract: The influence of the proton transfer on the geometry of donor and acceptor molecule in benzoic acid-pyridine complexes is investigated by theoretical calculations at the B3LYP/6-311++G∗ level of theory. Systematic shifts of the H-atom in the H-bond are reflected in the geometry of the COOH group and the lengths of aromatic ring bond lengths of the proton acceptor. Changes in electron densities have been studied by atoms in molecules analysis. A systematic natural bond orbital analysis has been performed to study the proton transfer mechanism. Two donor orbitals are engaged in the proton transfer process which is accompanied by a change in orbital delocalization of H-atom that can switch between two donor orbitals so the path of proton transfer in intermolecular H-bond is not determined by the orbital shape. Theoretical results have been confirmed by experimental results published previously. |
BibTeX:
@article{Majerz2016,
author = {Majerz, I.},
title = {Proton Transfer Influence on Geometry and Electron Density in Benzoic Acid-Pyridine Complexes},
journal = {Helv. Chim. Acta},
year = {2016},
volume = {99},
number = {4},
pages = {286--295},
doi = {10.1002/hlca.201500183}
}
|
| Mazuryk J, Deptuła T, Polchi A, Gapiński J, Giovagnoli S, Magini A, Emiliani C, Kohlbrecher J and Patkowski A (2016), "Rapamycin-loaded solid lipid nanoparticles: Morphology and impact of the drug loading on the phase transition between lipid polymorphs", Colloids Surfaces A Physicochem. Eng. Asp.. Vol. 502, pp. 54-65. |
| Abstract: In recent decades solid lipid nanoparticles (SLN) have become a well-performing tool for the site-targeted delivery of water-insoluble drugs. In this study, Compritol® 888 ATO-based SLN, coated with polysorbate 80, were loaded with rapamycin (Rap), a lipophilic immunomodulator, broadly-used in therapies of cancer and neurodegenerative diseases. Rap-SLN were formulated using cold high-pressure homogenization and ultrasound-assisted emulsion. The exploitation of these methods yielded the nanoparticles of various values of zeta-potential (from -1 mV to -20 mV) and efficacies of the Rap entrapment (from 37.5 ± 2.3% to 77.0 ± 5.4%). The SEM and AFM imaging and shape-modeling by the combined DLS-SANS analysis revealed that the Rap-SLN of the hydrodynamic radius of ∼46 nm preserve the platelet-like or flat ellipsoidal structure with a thickness as large as 8-9 nm. These dimensions correspond to a single lipid bilayer, organized in a triclinic Lβ polymorph, and covered with a 1-2-nm shell of the surfactant. Consistently, FT-IR spectra acquired in the range 52-75 °C, showed that the Rap incorporation within the lipid matrix decreases the point of the gel-liquid crystalline (Lβ-Lα) phase transition. These outcomes imply a thermodynamically-driven mechanism of the Rap release from SLN. |
BibTeX:
@article{Mazuryk2016,
author = {Mazuryk, J. and Deptuła, T. and Polchi, A. and Gapiński, J. and Giovagnoli, S. and Magini, A. and Emiliani, C. and Kohlbrecher, J. and Patkowski, A.},
title = {Rapamycin-loaded solid lipid nanoparticles: Morphology and impact of the drug loading on the phase transition between lipid polymorphs},
journal = {Colloids Surfaces A Physicochem. Eng. Asp.},
year = {2016},
volume = {502},
pages = {54--65},
doi = {10.1016/j.colsurfa.2016.05.017}
}
|
| Nieroda P, Kolezynski A, Oszajca M, Milczarek J and Wojciechowski KT (2016), "Structural and Thermoelectric Properties of Polycrystalline p-Type Mg2−xLixSi", J. Electron. Mater., Jul, 2016. Vol. 45(7), pp. 3418-3426. |
| Abstract: The aim of this study was to determine the location of Li atoms in Mg2Si structure, and verify the influence of Li dopant on the transport properties of obtained thermoelectric materials. The results of theoretical studies of the electronic band structure (full potential linearized augmented plane wave method) in Li-doped Mg2Si are presented. Theoretical calculations indicate that only in the case when Li is located in the Mg position, the samples will have p-type conduction. To confirm the theoretical predictions, a series of samples with nominal composition Mg2−xLixSi (x = 0–0.5) were prepared using the spark plasma sintering (SPS) method. Structural and phase composition analyses were carried out by x-ray and neutron powder diffraction, as well as scanning electron microscopy. Neutron diffraction studies confirmed that the lithium atoms substitute magnesium in the Mg2Si structure. The investigations of the influence of Li dopant on the transport properties, i.e. electrical conductivity, the Seebeck coefficient and the thermal conductivity, were carried out in a temperature range from 340 K to 720 K. Carrier concentration was measured with Hall method. The positive values of the Seebeck coefficient and Hall coefficient indicate that all examined samples show p-type conductivity. On the basis of the experimental data, the temperature dependencies of the thermoelectric figure of merit ZT were calculated. |
BibTeX:
@article{Nieroda2016,
author = {Nieroda, P. and Kolezynski, A. and Oszajca, M. and Milczarek, J. and Wojciechowski, K. T.},
title = {Structural and Thermoelectric Properties of Polycrystalline p-Type Mg2−x Li x Si},
journal = {J. Electron. Mater.},
year = {2016},
volume = {45},
number = {7},
pages = {3418--3426},
url = {http://link.springer.com/10.1007/s11664-016-4486-5},
doi = {10.1007/s11664-016-4486-5}
}
|
| Ondrejkovic P, Kempa M, Savinov M, Bednyakov P, Kulda J, Bourges P, Dec J and Hlinka J (2016), "Electric-field influence on the neutron diffuse scattering near the ferroelectric transition of Sr0.61Ba0.39Nb2O6", Phase Transitions., Aug, 2016. Vol. 89(7-8), pp. 808-815. |
| Abstract: Uniaxial relaxor ferroelectric Sr0.61Ba0.39Nb2O6 single crystal has been investigated in the vicinity of its phase transition using neutron scattering and dielectric spectroscopy. A global-type thermal hysteresis is evidenced by both techniques in the ferroelectric phase and up to about 15 K above Tc. In addition, a part of the transverse neutron diffuse scattering in the 001 Brillouin zone, presumably related to static nanodomain structure, can be suppressed by prior poling the crystal in electric field of 3 kV/cm. The remaining part of the transverse neutron diffuse scattering and the real part of permittivity show a similar temperature dependence. The temperature position of the maximal scattering intensity Tmax depends significantly on the scattering wave vector. Tmax shifts monotonically to higher temperature with the increasing wave vector in all investigated cooling and heating regimes. It is concluded that the critical fluctuations have space correlations which depend on frequency and wave vector. |
BibTeX:
@article{Ondrejkovic2016,
author = {Ondrejkovic, Petr and Kempa, Martin and Savinov, Maxim and Bednyakov, Petr and Kulda, Jiri and Bourges, Philippe and Dec, Jan and Hlinka, Jirka},
title = {Electric-field influence on the neutron diffuse scattering near the ferroelectric transition of Sr0.61Ba0.39Nb2O6},
journal = {Phase Transitions},
year = {2016},
volume = {89},
number = {7-8},
pages = {808--815},
url = {https://www.tandfonline.com/doi/full/10.1080/01411594.2016.1186275},
doi = {10.1080/01411594.2016.1186275}
}
|
| Ordon M, Gorshkova Y and Ossowska-Chruściel M (2016), "Lithocholic acid derivative in the presence of dimethyl sulfoxide: Morphology and phase transitions", Thermochim. Acta. Vol. 643, pp. 1-12. |
| Abstract: We report on the properties of a new organogelator, which is an ether derivative of lithocholic acid (7OPhOLCA). The correctness of the chemical structure and purity of 7OPhOLCA was confirmed by thin layer chromatography, proton nuclear magnetic resonance (1H NMR) spectroscopy, elemental analysis (EA) and infrared spectroscopy (IR). Phase transition temperatures and enthalpies of the gel were obtained by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). Changes in the vibrational spectra depending on the temperature modifications were studied using the technique of FTIR Spectroscopy with 2D correlation analysis. The small angle neutron scattering method (SANS) was used to determine the morphology and internal structure of the investigated system. It was found that the substance forms a non-transparent stable gel with a spherulite organization at the macro-scale level. The morphology of the self-assemblies and internal structure at the nano-scale level are quite different with variation of the temperature in the Gel phase. A further increase in temperature leads to the formation of the sol phase again. It turns out that the temperature of the gel-sol transition changes significantly with the concentration of 7OPhOLCA. The results of the DSC and SANS measurements indicated the reversible behavior of the Gel-SolGel transition with hysteresis on the temperature during heating and cooling. |
BibTeX:
@article{Ordon2016,
author = {Ordon, M. and Gorshkova, Y. and Ossowska-Chruściel, M.D.},
title = {Lithocholic acid derivative in the presence of dimethyl sulfoxide: Morphology and phase transitions},
journal = {Thermochim. Acta},
year = {2016},
volume = {643},
pages = {1--12},
doi = {10.1016/j.tca.2016.09.013}
}
|
| Pajzderska A, Drużbicki K, Kiwilsza A, Gonzalez M, Jenczyk J, Jurga S, Mielcarek J and Waşicki J (2016), "On the molecular dynamics in long-acting calcium channel blocker lacidipine: Solid-state NMR, neutron scattering and periodic DFT study", RSC Adv.. Vol. 6(71), pp. 66617-66629. |
| Abstract: Molecular and vibrational dynamics of a new-generation lipophilic calcium channel blocker lacidipine (LCDP) are thoroughly explored by combining solid-state nuclear magnetic resonance (NMR) with high-flux quasi-elastic (QENS) and inelastic neutron scattering (INS) experiments. Contrary to the dynamically averaged 13C CP/MAS NMR response, neutron vibrational spectroscopy confirms our previous findings on the thermodynamically stable structure. High-resolution low-wavenumber INS spectrum is reported and fully interpreted based on periodic density functional theory (DFT) calculations in the quasi-harmonic approximation, staying in excellent agreement with the experiment. The INS spectrum was found to be clearly dominated by CH3 torsional features, widely spread over the range of 5-35 meV. 1H NMR relaxation indicates a molecular reorientation with different correlation times. The NMR relaxometry was further combined with an extended QENS study, providing a quantitative description of the intramolecular motions in terms of their activation barriers and correlation times, while their assignment was fully supported by theoretical analysis. While the internal dynamics of side-chain methyl groups can be described by rotation about the threefold-axes, the high-resolution QENS measurements give evidence of rotational tunneling of 2,6-methyl groups at low temperature. The vibrational analysis suggests that strong coupling of methyl librations with lattice modes promotes such an intriguing quantum effect. |
BibTeX:
@article{Pajzderska2016,
author = {Pajzderska, A. and Druzbicki, K. and Kiwilsza, A. and Gonzalez, M.A. and Jenczyk, J. and Jurga, S. and Mielcarek, J. and Waşicki, J.},
title = {On the molecular dynamics in long-acting calcium channel blocker lacidipine: Solid-state NMR, neutron scattering and periodic DFT study},
journal = {RSC Adv.},
year = {2016},
volume = {6},
number = {71},
pages = {66617--66629},
doi = {10.1039/c6ra07117a}
}
|
| Paul-Boncour V, Filipek SM, Crivello JC, Couturas F and Morawski A (2016), "Properties of ZrNi5 deuteride synthesized under high pressure studied by neutron diffraction and first principles calculations", Int. J. Hydrogen Energy., Oct, 2016. Vol. 41(39), pp. 17408-17420. |
| Abstract: ZrNi5 deuteride was synthesized at a high deuterium pressure of 0.9 GPa and at 373 K. Neutron diffraction study has revealed that ZrNi5D0.96(4) crystallizes in a monoclinic structure (Cm space group) between 1.8 and 220 K. The D atoms are located in one trigonal bipyramid Zr2Ni3 interstitial site. Between 220 and 265 K a first order transition from the ordered monoclinic structure towards a disordered cubic structure is observed. In addition, a small deuterium desorption was observed after several hours at 240 K. Above 270 K, the compound is fully cubic and an accelerated deuterium desorption is observed within a two phase transformation. The kinetic of monoclinic-cubic transformation followed at 240 K is very slow, and the structural transformation is found reversible upon cooling. First principles calculations were performed in the frame of the Density Functional Theory (DFT) to understand the formation of the low temperature ZrNi5H1 hydride and its vibration properties. |
BibTeX:
@article{Paul-Boncour2016,
author = {Paul-Boncour, V. and Filipek, S. M. and Crivello, J. C. and Couturas, F. and Morawski, A.},
title = {Properties of ZrNi5 deuteride synthesized under high pressure studied by neutron diffraction and first principles calculations},
journal = {Int. J. Hydrogen Energy},
year = {2016},
volume = {41},
number = {39},
pages = {17408--17420},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0360319916321188},
doi = {10.1016/j.ijhydene.2016.07.127}
}
|
| Pavlosiuk O, Kaczorowski D, Fabreges X, Gukasov A and Wiśniewski P (2016), "Antiferromagnetism and superconductivity in the half-Heusler semimetal HoPdBi", Sci. Rep., Jan, 2016. Vol. 6(1), pp. 18797. |
| Abstract: We observed the coexistence of superconductivity and antiferromagnetic order in the single-crystalline ternary pnictide HoPdBi, a plausible topological semimetal. The compound orders antiferromagnetically at T N = 1.9 K and exhibits superconductivity below T c = 0.7 K, which was confirmed by magnetic, electrical transport and specific heat measurements. The specific heat shows anomalies corresponding to antiferromagnetic ordering transition and crystalline field effect, but not to superconducting transition. Single-crystal neutron diffraction indicates that the antiferromagnetic structure is characterized by the "Equation missing" propagation vector. Temperature variation of the electrical resistivity reveals two parallel conducting channels of semiconducting and metallic character. In weak magnetic fields, the magnetoresistance exhibits weak antilocalization effect, while in strong fields and temperatures below 50 K it is large and negative. At temperatures below 7 K Shubnikov-de Haas oscillations with two frequencies appear in the resistivity. These oscillations have non-trivial Berry phase, which is a distinguished feature of Dirac fermions. |
BibTeX:
@article{Pavlosiuk2016,
author = {Pavlosiuk, Orest and Kaczorowski, Dariusz and Fabreges, Xavier and Gukasov, Arsen and Wiśniewski, Piotr},
title = {Antiferromagnetism and superconductivity in the half-Heusler semimetal HoPdBi},
journal = {Sci. Rep.},
year = {2016},
volume = {6},
number = {1},
pages = {18797},
url = {https://www.nature.com/articles/srep18797},
doi = {10.1038/srep18797}
}
|
| Pawlukojć A and Hetmańczyk (2016), "INS, DFT and temperature dependent IR studies on dynamical properties of acetylcholine chloride", Vib. Spectrosc.. Vol. 82, pp. 37-43. |
| Abstract: The acetylcholine chloride (2-acetoxy-N,N,N-trimethylethanaminium chloride) was investigation by inelastic neutron scattering and temperature dependent infrared spectroscopy. The infrared spectra in the temperature range 9-300 K were collected. The density functional theory calculation with the periodic boundary conditions was used for an experimental data analysis. Bands assigned to the CH3 torsion vibration in the acetylcholine cation were observed at 207, 296, 345 and 359 cm-1 in INS spectrum. Activation energy for reorientational motion of the whole N-(CH3)3 fragment was determined by means of band shape analysis performed for symmetric stretching vibration of this group. The estimated energy is equal to Ea = 5.3(3) kJ/mol. |
BibTeX:
@article{Pawlukojc2016,
author = {Pawlukojć, A. and Hetmańczyk, .},
title = {INS, DFT and temperature dependent IR studies on dynamical properties of acetylcholine chloride},
journal = {Vib. Spectrosc.},
year = {2016},
volume = {82},
pages = {37--43},
doi = {10.1016/j.vibspec.2015.11.008}
}
|
| Penc B, Hoser A and Szytuła A (2016), "Neutron diffraction studies of PrNi5Sn", Acta Phys. Pol. A., Mar, 2016. Vol. 129(3), pp. 313-314. |
| Abstract: Powder neutron diffraction measurements of PrNi5Sn performed in the temperature range 1.5-76 K indicate that the compound crystallizes in a hexagonal CeNi5Sn-type crystal structure (space group P63=mmc). The a lattice parameter and the unit cell volume V increase while the c lattice parameter does not change with increasing temperature. No long range magnetic ordering was detected down to 1.5 K, in contradiction to bulk magnetometric results. |
BibTeX:
@article{Penc2016,
author = {Penc, B. and Hoser, A. and Szytuła, A.},
title = {Neutron diffraction studies of PrNi5Sn},
journal = {Acta Phys. Pol. A},
year = {2016},
volume = {129},
number = {3},
pages = {313--314},
url = {http://przyrbwn.icm.edu.pl/APP/PDF/129/a129z3p09.pdf},
doi = {10.12693/APhysPolA.129.313}
}
|
| Prylutskyy Y, Borowik A, Gołuński G, Woziwodzka A, Piosik J, Kyzyma O, Pashkova I, Ritter U and Evstigneev M (2016), "Biophysical characterization of the complexation of C60 fullerene with doxorubicin in a prokaryotic model", Materwiss. Werksttech., Mar, 2016. Vol. 47(2-3), pp. 92-97. |
| Abstract: By means of small-angle neutron scattering and ames mutagenicity test it was shown that C60 fullerene may act as an interceptor of the antibiotic doxorubicin by formation of a hetero-complex with this drug. This result has been predicted based on previously developed model of chemico-biological interaction between DNA-binding drugs and aromatic interceptor molecules. |
BibTeX:
@article{Prylutskyy2016,
author = {Prylutskyy, Y. and Borowik, A. and Gołuński, G. and Woziwodzka, A. and Piosik, J. and Kyzyma, O. and Pashkova, I. and Ritter, U. and Evstigneev, M.},
title = {Biophysical characterization of the complexation of C 60 fullerene with doxorubicin in a prokaryotic model},
journal = {Materwiss. Werksttech.},
year = {2016},
volume = {47},
number = {2-3},
pages = {92--97},
url = {https://onlinelibrary.wiley.com/doi/10.1002/mawe.201600463},
doi = {10.1002/mawe.201600463}
}
|
| Radwanski RJ, Nalecz DM and Ropka Z (2016), "Three localized f electrons in UPd2Al3 and in UGe2 intermetallics", In Acta Phys. Pol. A., Aug, 2016. Vol. 130(2), pp. 545-550. |
| Abstract: We have calculated the strength of the excitations between the crystal-field states which are in agreement with inelastic-neutron-scattering results. This agreement confirms the existence in the heavy-fermion superconductor UPd2Al3 the crystal-field electronic structure being the finger-print of the U3+ ions with three localized f electrons forming strongly-correlated atomic-like quantum system 5f3. The ionic integrity and the low-energy crystal-field electronic structure is preserved in this metallic system in the meV scale as has been postulated in the Quantum Atomistic Solid State theory (QUASST). We provide preliminary results with the U3+ ion in UGe2 showing the ground-state eigenfunction which reproduces the ordered magnetic-moment value of 1.48 μB. This moment is composed from the dominant orbital contribution (2.6 μB) and the opposite spin moment (1.12 μB). |
BibTeX:
@inproceedings{Radwanski2016,
author = {Radwanski, R. J. and Nalecz, D. M. and Ropka, Z.},
title = {Three localized f electrons in UPd2Al3 and in UGe2 intermetallics},
booktitle = {Acta Phys. Pol. A},
year = {2016},
volume = {130},
number = {2},
pages = {545--550},
url = {http://przyrbwn.icm.edu.pl/APP/PDF/130/a130z2p08.pdf},
doi = {10.12693/APhysPolA.130.545}
}
|
| Rajewska A, Medrzycka K, Hallmann E and Soloviov D (2016), "Small-angle neutron scattering study of the structure of mixed micellar solutions based on heptaethylene glycol monotetradecyl ether and cesium dodecyl sulfate", Crystallogr. Reports. Vol. 61(1), pp. 126-128. |
| Abstract: The micellization in mixed aqueous systems based on a nonionic surfactant, heptaethylene glycol monotetradecyl ether (C14E7), and an anionic surfactant, cesium dodecyl sulfate, has been investigated by small-angle neutron scattering. Preliminary data on the behavior of the C14E7 aqueous solutions (with three concentrations, 0.17, 0.5, and 1%) mixed with a small amount of anionic surfactant, cesium dodecyl sulfate, are reported. |
BibTeX:
@article{Rajewska2016,
author = {Rajewska, A. and Medrzycka, K. and Hallmann, E. and Soloviov, D.V.},
title = {Small-angle neutron scattering study of the structure of mixed micellar solutions based on heptaethylene glycol monotetradecyl ether and cesium dodecyl sulfate},
journal = {Crystallogr. Reports},
year = {2016},
volume = {61},
number = {1},
pages = {126--128},
doi = {10.1134/S1063774516010181}
}
|
| von Rohr F, Krzton-Maziopa A, Pomjakushin V, Grundmann H, Guguchia Z, Schnick W and Schilling A (2016), "Field-induced transition of the magnetic ground state from A-type antiferromagnetic to ferromagnetic order in CsCo2 Se2", J. Phys. Condens. Matter., Jul, 2016. Vol. 28(27), pp. 276001. |
| Abstract: We report on the magnetic properties of CsCo2Se2 with ThCr2Si2 structure, which we have characterized through a series of magnetization and neutron diffraction measurements. We find that CsCo2Se2 undergoes a phase transition to an antiferromagnetically ordered state with a Néel temperature of K. The nearest neighbour interactions are ferromagnetic as observed by the positive Curie-Weiss temperature of K. We find that the magnetic structure of CsCo2Se2 consists of ferromagnetic sheets, which are stacked antiferromagnetically along the tetragonal c-axis, generally referred to as A-type antiferromagnetic order. The observed magnitude of the ordered magnetic moment at T = 1.5 K is found to be only 0.20(1) / Co. Already in comparably small magnetic fields of T, we observe a metamagnetic transition that can be attributed to spin-rearrangements of CsCo2Se2, with the moments fully ferromagnetically saturated in a magnetic field of T. We discuss the entire experimentally deduced magnetic phase diagram for CsCo2Se2 with respect to its unconventionally weak magnetic coupling. Our study characterizes CsCo2Se2, which is chemically and electronically posed closely to the AxFe2-ySe2 superconductors, as a host of versatile magnetic interactions. |
BibTeX:
@article{VonRohr2016,
author = {von Rohr, Fabian and Krzton-Maziopa, Anna and Pomjakushin, Vladimir and Grundmann, Henrik and Guguchia, Zurab and Schnick, Wolfgang and Schilling, Andreas},
title = {Field-induced transition of the magnetic ground state from A-type antiferromagnetic to ferromagnetic order in CsCo 2 Se 2},
journal = {J. Phys. Condens. Matter},
year = {2016},
volume = {28},
number = {27},
pages = {276001},
url = {https://iopscience.iop.org/article/10.1088/0953-8984/28/27/276001},
doi = {10.1088/0953-8984/28/27/276001}
}
|
| Sanjuan-Szklarz W, Hoser A, Gutmann M, Madsen A and Woźniak K (2016), "Yes, one can obtain better quality structures from routine X-ray data collection", IUCrJ. Vol. 3, pp. 61-70. |
| Abstract: Single-crystal X-ray diffraction structural results for benzidine dihydrochloride, hydrated and protonated N,N,N,N-peri(dimethylamino)naphthalene chloride, triptycene, dichlorodimethyltriptycene and decamethylferrocene have been analysed. A critical discussion of the dependence of structural and thermal parameters on resolution for these compounds is presented. Results of refinements against X-ray data, cut off to different resolutions from the high-resolution data files, are compared to structural models derived from neutron diffraction experiments. The Independent Atom Model (IAM) and the Transferable Aspherical Atom Model (TAAM) are tested. The average differences between the X-ray and neutron structural parameters (with the exception of valence angles defined by H atoms) decrease with the increasing 2θmax angle. The scale of differences between X-ray and neutron geometrical parameters can be significantly reduced when data are collected to the higher, than commonly used, 2θmax diffraction angles (for Mo Kα 2θmax > 65°). The final structural and thermal parameters obtained for the studied compounds using TAAM refinement are in better agreement with the neutron values than the IAM results for all resolutions and all compounds. By using TAAM, it is still possible to obtain accurate results even from low-resolution X-ray data. This is particularly important as TAAM is easy to apply and can routinely be used to improve the quality of structural investigations [Dominiak (2015). LSDB from UBDB. University of Buffalo, USA]. We can recommend that, in order to obtain more adequate (more accurate and precise) structural and displacement parameters during the IAM model refinement, data should be collected up to the larger diffraction angles, at least, for Mo Kα radiation to 2θmax = 65° (sin θmax/λ < 0.75 Å-1). The TAAM approach is a very good option to obtain more adequate results even using data collected to the lower 2θmax angles. Also the results of translation-libration-screw (TLS) analysis and vibrational entropy values are more reliable for 2θmax > 65°. |
BibTeX:
@article{Sanjuan-Szklarz2016,
author = {Sanjuan-Szklarz, W.F. and Hoser, A.A. and Gutmann, M. and Madsen, A.O. and Woźniak, K.},
title = {Yes, one can obtain better quality structures from routine X-ray data collection},
journal = {IUCrJ},
year = {2016},
volume = {3},
pages = {61--70},
doi = {10.1107/S2052252515020941}
}
|
| Szostak E, Hetmańczyk J and Migdał-Mikuli A (2016), "Low-temperature phase transition in [Cd(OS(CH3)2)6](ClO4)2 studied by inelastic and elastic neutron scattering, Raman light scattering, and infrared absorption spectroscopy", Vib. Spectrosc., May, 2016. Vol. 84, pp. 83-91. |
| Abstract: The vibrational and reorientational dynamics of CH3 groups from (CH3)2SO ligands in the high- and low-temperature phases of [Cd(OS(CH3)2)6](ClO4)2 were investigated by Fourier transform infrared (FT-IR) and Raman (FT-Raman) spectroscopy, and quasielastic and inelastic incoherent neutron scattering (QENS and IINS) methods. The results show that in the high temperature phases the CH3 groups and ClO4- anions perform fast (τR ≈ 10-12 s) reorientational motions. These molecular motions do not change significantly at low-temperature phase transition (detected earlier by differential scanning calorimetry (DSC) at TC4c=235 K on cooling and at TC4c=242 K on heating). Neutron powder diffraction (NPD) measurements, performed simultaneously with QENS and IINS, indicated that this phase transition is associated with a change of the crystal structure. The comparison of FT-IR, FT-Raman and the proton-weighted phonon density of states function G(ν) calculated from IINS experimental spectra at low temperature phase of [Cd(OS(CH3)2)6](ClO4)2 was made. |
BibTeX:
@article{Szostak2016,
author = {Szostak, Elżbieta and Hetmańczyk, Joanna and Migdał-Mikuli, Anna},
title = {Low-temperature phase transition in [Cd(OS(CH3)2)6](ClO4)2 studied by inelastic and elastic neutron scattering, Raman light scattering, and infrared absorption spectroscopy},
journal = {Vib. Spectrosc.},
year = {2016},
volume = {84},
pages = {83--91},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0924203116300327},
doi = {10.1016/j.vibspec.2016.03.006}
}
|
| Szuszkiewicz W, Ott F, Kisielewski J, Sveklo I, Dynowska E, Minikayev R, Kurant Z, Kuna R, Jakubowski M, Wawro A, Sobierajski R and Maziewski A (2016), "Polarized neutron reflectivity and X-ray scattering measurements as tools to study properties of Pt/Co/Pt ultrathin layers irradiated by femtosecond laser pulses", Phase Transitions. Vol. 89(4), pp. 328-340. |
| Abstract: We have used polarized neutron reflectivity, X-ray diffraction, X-ray reflectivity and magneto-optical Kerr effect in polar configuration to study the properties of ultrathin Pt/Co/Pt films. Structures consisting of a 5-nm thick Pt buffer, 3-nm thick Co layer and 5-nm thick Pt cover layer were deposited onto (0001)-oriented Al2O3 substrate by the molecular beam epitaxy (MBE) method. Irreversible modifications of film properties, resulting from its illumination by single femtosecond laser pulses, of duration of 40 fs and wavelength of 800 nm, were observed and analyzed. As prepared films exhibited magnetization in-plane, but after laser irradiation, the direction of magnetization was rotated to out-of-plane state. Formation of Co-Pt alloy phase caused by quasi-uniform film irradiation was demonstrated by the results of X-ray and neutron scattering measurements. Moreover, polarized neutron and X-ray reflectivity data showed that after illumination Co was distributed mostly in the area of nominal Co layer and Pt cover layer and its diffusion into the Pt buffer was less significant. |
BibTeX:
@article{Szuszkiewicz2016,
author = {Szuszkiewicz, W. and Ott, F. and Kisielewski, J. and Sveklo, I. and Dynowska, E. and Minikayev, R. and Kurant, Z. and Kuna, R. and Jakubowski, M. and Wawro, A. and Sobierajski, R. and Maziewski, A.},
title = {Polarized neutron reflectivity and X-ray scattering measurements as tools to study properties of Pt/Co/Pt ultrathin layers irradiated by femtosecond laser pulses},
journal = {Phase Transitions},
year = {2016},
volume = {89},
number = {4},
pages = {328--340},
doi = {10.1080/01411594.2016.1156110}
}
|
| Szytuła A, Hoser A, Baran S and Penc B (2016), "Evidence of the non-magnetic ordering in TmRu2Si2 at low temperatures", Acta Phys. Pol. A., Dec, 2016. Vol. 130(6), pp. 1371-1372. |
| Abstract: The neutron powder diffraction measurements of the TmRu2Si2 compound in the temperature range 0.47-2.5 K have been performed. The obtained results confirm that this compound in low temperature has a tetragonal ThCr2Si2-type crystal structure (space group I4/mmm). The long range magnetic ordering was not detected up to 0.47 K. |
BibTeX:
@article{Szytua2016,
author = {Szytuła, A. and Hoser, A. and Baran, S. and Penc, B.},
title = {Evidence of the non-magnetic ordering in TmRu2Si2 at low temperatures},
journal = {Acta Phys. Pol. A},
year = {2016},
volume = {130},
number = {6},
pages = {1371--1372},
url = {http://przyrbwn.icm.edu.pl/APP/PDF/130/a130z6p16.pdf},
doi = {10.12693/APhysPolA.130.1371}
}
|
| Abstract: The neutron time of flight (n-TOF) facility at CERN is a spallation source characterized by a white neutron spectrum. The innovative features of the facility, in the two experimental areas, (20 m and 185 m), allow for an accurate determination of the neutron cross section for radioactive samples or for isotopes with small neutron capture cross section, of interest for Nuclear Astrophysics. The recent results obtained at n-TOF facility are presented. |
BibTeX:
@inproceedings{Tagliente2016,
author = {Tagliente, G. and Aberle, O. and Andrzejewski, J. and Audouin, L. and Bacak, M. and Balibrea, J. and Barbagallo, M. and Bečváf, F. and Berthoumieux, E. and Billowes, J. and Wright, T. and Zugec, P.Č.},
title = {Recent results in nuclear astrophysics at the n-TOF facility at CERN},
booktitle = {Proc. Sci.},
year = {2016},
volume = {2016-Septe}
}
|
| Wang Y, Wang L, Zheng H, Li K, Andrzejewski M, Hattori T, Sano-Furukawa A, Katrusiak A, Meng Y, Liao F, Hong F and Mao HK (2016), "Phase Transitions and Polymerization of C6H6-C6F6 Cocrystal under Extreme Conditions", J. Phys. Chem. C., Dec, 2016. Vol. 120(51), pp. 29510-29519. |
| Abstract: Pressure-induced polymerization (PIP) of aromatic molecules can generate saturated carbon nanostructures. As a strongly interacted π-π stacking unit, the C6H6-C6F6 adduct is widely applied in supramolecular chemistry, and it provides a good preorganization for the PIP. Here we investigated the structural variation of C6H6-C6F6 cocrystal and the subsequent PIP process under high pressure. Four new molecular-complex phases V, VI, VII, and VIII have been identified and characterized by the in situ Raman, IR, synchrotron X-ray, and neutron diffraction. The phase V is different from the phases observed at low temperature, which has a tilted column structure. Phases VI and VII have a structure similar to phase V. Phase VIII polymerizes irreversibly upon compression above 25 GPa without any catalyst, producing sp3(CH/F)n materials. The π-π interaction is still dominant below 0.5 GPa but is most likely to be overstepped under further compression, which is important for discussing the supramolecular phase transition and the polymerization process. |
BibTeX:
@article{Wang2016,
author = {Wang, Yajie and Wang, Lijuan and Zheng, Haiyan and Li, Kuo and Andrzejewski, Michał and Hattori, Takanori and Sano-Furukawa, Asami and Katrusiak, Andrzej and Meng, Yufei and Liao, Fuhui and Hong, Fang and Mao, Ho Kwang},
title = {Phase Transitions and Polymerization of C6H6-C6F6 Cocrystal under Extreme Conditions},
journal = {J. Phys. Chem. C},
year = {2016},
volume = {120},
number = {51},
pages = {29510--29519},
url = {https://pubs.acs.org/doi/10.1021/acs.jpcc.6b11245},
doi = {10.1021/acs.jpcc.6b11245}
}
|
| Wdowik UD, Piekarz P, Legut D and Jagło G (2016), "Effect of spin-orbit and on-site Coulomb interactions on the electronic structure and lattice dynamics of uranium monocarbide", Phys. Rev. B., Aug, 2016. Vol. 94(5), pp. 054303. |
| Abstract: Uranium monocarbide, a potential fuel material for the generation IV reactors, is investigated within density functional theory. Its electronic, magnetic, elastic, and phonon properties are analyzed and discussed in terms of spin-orbit interaction and localized versus itinerant behavior of the 5f electrons. The localization of the 5f states is tuned by varying the local Coulomb repulsion interaction parameter. We demonstrate that the theoretical electronic structure, elastic constants, phonon dispersions, and their densities of states can reproduce accurately the results of x-ray photoemission and bremsstrahlung isochromat measurements as well as inelastic neutron scattering experiments only when the 5f states experience the spin-orbit interaction and simultaneously remain partially localized. The partial localization of the 5f electrons could be represented by a moderate value of the on-site Coulomb interaction parameter of about 2 eV. The results of the present studies indicate that both strong electron correlations and spin-orbit effects are crucial for realistic theoretical description of the ground-state properties of uranium carbide. |
BibTeX:
@article{Wdowik2016,
author = {Wdowik, U. D. and Piekarz, P. and Legut, D. and Jagło, G.},
title = {Effect of spin-orbit and on-site Coulomb interactions on the electronic structure and lattice dynamics of uranium monocarbide},
journal = {Phys. Rev. B},
year = {2016},
volume = {94},
number = {5},
pages = {054303},
url = {https://link.aps.org/doi/10.1103/PhysRevB.94.054303},
doi = {10.1103/PhysRevB.94.054303}
}
|
| Woińska M, Grabowsky S, Dominiak PM, Woźniak K and Jayatilaka D (2016), "Hydrogen atoms can be located accurately and precisely by x-ray crystallography", Sci. Adv., May, 2016. Vol. 2(5) |
| Abstract: Hydrogen atoms cannot hide from x-rays anymore but can instead be detected very reliably in routine measurements. |
BibTeX:
@article{Woinska2016,
author = {Woińska, Magdalena and Grabowsky, Simon and Dominiak, Paulina M. and Woźniak, Krzysztof and Jayatilaka, Dylan},
title = {Hydrogen atoms can be located accurately and precisely by x-ray crystallography},
journal = {Sci. Adv.},
year = {2016},
volume = {2},
number = {5},
url = {https://www.science.org/doi/10.1126/sciadv.1600192},
doi = {10.1126/sciadv.1600192}
}
|
| Łuczyńska K, Druzbicki K, Lyczko K and Dobrowolski J (2016), "Structure-Spectra Correlations in Anilate Complexes with Picolines", Cryst. Growth Des.. Vol. 16(10), pp. 6069-6083. |
| Abstract: We report a joint structural and spectroscopic study of a series of hydrogen-bonded chloranilate and bromanilate complexes with α- and β-picolines. Single-crystal structures at 100 K are provided for all the systems analyzed, which were found to form B:XA:XA:B,:(B:XA:B):XA, and B:XA:B type synthons, where XA and B stand for the acid and base molecules, respectively. By extending single-crystal X-ray crystallography onto computationally supported high-resolution solid-state spectroscopy, we provide a comprehensive analysis of spectral signatures that can possibly facilitate the design and recognition of the supramolecular architectures formed by these kinds of synthons. To this end, we employed nuclear magnetic resonance spectroscopy along with complementary optical (infrared, Raman, terahertz time-domain spectroscopy) and neutron (inelastic neutron scattering) vibrational techniques. Despite a large chemical similarity, the studied systems exhibited strikingly different spectral responses. All the spectral signatures and peculiarities arising from structural factors, intermolecular forces, and specific effects are interpreted and discussed in detail. Based on state-of-the-art first-principles calculations for solid-state, in both static and time-evolved manners, the spectral influences of long-range dipole coupling, proton transfer, symmetry-distortion, as well as anharmonicity are covered extensively. In this way, we take the necessary first step needed to gather combined structure-spectroscopy data on low-weight supramolecular synthons, which are important in crystal engineering and materials science. |
BibTeX:
@article{uczynska2016,
author = {Łuczyńska, K. and Druzbicki, K. and Lyczko, K. and Dobrowolski, J.Cz.},
title = {Structure-Spectra Correlations in Anilate Complexes with Picolines},
journal = {Cryst. Growth Des.},
year = {2016},
volume = {16},
number = {10},
pages = {6069--6083},
doi = {10.1021/acs.cgd.6b01114}
}
|
| Al-Zein A, Bouvier P, Kania A, Levelut C, Hehlen B, Nassif V, Hansen TC, Fertey P, Haines J and Rouquette J (2015), "High pressure single crystal x-ray and neutron powder diffraction study of the ferroelectric–paraelectric phase transition in PbTiO3", J. Phys. D. Appl. Phys., Dec, 2015. Vol. 48(50), pp. 504008. |
| Abstract: The results obtained by high pressure neutron powder diffraction and single-crystal x-ray diffraction for the P4mm-Pm m phase transition in the prototype ferroelectric perovskite lead titanate are shown. Neutron diffraction is found to be strongly sensitive to the dipolar moment in the PbTiO3 unit cell due to the gradual reduction of the displacement of the Ti and O atoms from centrosymmetric positions in the cubic perovskite structure which exhibits anti-phase scattering of Pb, Ti and O atoms. From applying both techniques, the anomalously high Debye-Waller factor for the lead atoms confirms the disordered character of the cubic phase. High pressure single crystal x-ray diffraction also perfectly describes the ferroelectric-paraelectric transition and will be the technique of choice to solve higher pressure structures for PbTiO3. |
BibTeX:
@article{Al-Zein2015,
author = {Al-Zein, A. and Bouvier, P. and Kania, A. and Levelut, C. and Hehlen, B. and Nassif, V. and Hansen, T C and Fertey, P. and Haines, J. and Rouquette, J.},
title = {High pressure single crystal x-ray and neutron powder diffraction study of the ferroelectric–paraelectric phase transition in PbTiO 3},
journal = {J. Phys. D. Appl. Phys.},
year = {2015},
volume = {48},
number = {50},
pages = {504008},
url = {https://iopscience.iop.org/article/10.1088/0022-3727/48/50/504008},
doi = {10.1088/0022-3727/48/50/504008}
}
|
| Baczyński K, Markiewicz M and Pasenkiewicz-Gierula M (2015), "A computer model of a polyunsaturated monogalactolipid bilayer", Biochimie., Nov, 2015. Vol. 118, pp. 129-140. |
| Abstract: 1,2-di-O-acyl-3-O-β-d-galactopyranosyl-sn-glycerol (MGDG) is the main lipid component of thylakoid membranes of higher plants and algae. This monogalactolipid is thought of as a non-bilayer lipid but actually it can form both lamellar and nonlamellar phases. In this study, molecular dynamics (MD) simulations of the fully hydrated di-18:3 MGDG bilayer in the lamellar phase were carried out at 310 and 295 K for 200 and 450 ns, respectively, using the GROMACS 4 software package and OPLS-AA force field. At both temperatures, the lamellar phase of the systems was stable. The pure di-18:3 MGDG bilayer is the first step towards creating a computer model of the lipid matrix of the thylakoid membrane and the main aim of this study was to validate the computer model of di-18:3 MGDG in the bilayer and also to assess the properties of the bilayer. However, only a few of the predicted properties could be compared with those derived experimentally and in other MD simulations because of insufficient amount of such data. Thus, direct validation of the MGDG bilayer proved difficult. Therefore, in the validation process also an indirect approach was used, in which a computer model of the 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC) bilayer simulated at the same temperatures using the same force field as the MGDG bilayer was assessed. Successful validation of the DOPC bilayer parameterized in the OPLS-AA force field and similar properties of the MGDG molecules in the pure 18:3 MGDG and in binary 18:3 MGDG-PC bilayers indicate that the computer model of the MDGD molecule is faithful and the MGDG bilayer is representative on the time scales covered in these MD simulations. |
BibTeX:
@article{Baczynski2015,
author = {Baczynski, Krzysztof and Markiewicz, Michal and Pasenkiewicz-Gierula, Marta},
title = {A computer model of a polyunsaturated monogalactolipid bilayer},
journal = {Biochimie},
year = {2015},
volume = {118},
pages = {129--140},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0300908415002825},
doi = {10.1016/j.biochi.2015.09.007}
}
|
| Baszczuk A, Dabrowski B and Avdeev M (2015), "High temperature neutron diffraction studies of PrInO3 and the measures of perovskite structure distortion", Dalt. Trans.. Vol. 44(23), pp. 10817-10827. |
| Abstract: The crystal structure of PrInO3 was investigated in the temperature range 303-1123 K by high-resolution neutron-powder diffraction. The PrInO3 adopts a highly distorted variant of the perovskite structure with the orthorhombic Pnma space group in the whole temperature range investigated. The bond length and bond-angle analysis revealed a very slow tendency to decrease structural distortion with increasing temperature. Comparison of different parameters quantifying perovskite structure distortion calculated for PrInO3 and the similar PrAlO3 and PrGaO3 shows the advantage of using the tolerance factor t12 calculated for the 12-fold coordinated Pr by geometrical averaging of the individual interatomic distances. An additional advantage of the tolerance factor method results from the possibility of extending it to predict the average structural distortion and the geometrical stability of the perovskites at various temperatures once the accurate dependence of t(x,T,d) on the composition, temperature and oxygen content is found. By comparing PrInO3 with several AMO3 perovskites containing ions in the fixed oxidation state on the A and M crystal sites it was found that structural distortion and the tolerance factor t12 for PrInO3 are consistent with the empirical thermal expansion coefficient based on the bond strength calculation [R. M. Hazen, and C. T. Prewitt, Am. Mineral., 1977, 62(3-4), 309]. In contrast to perovskites AMO3-d containing mixed-valent M ions, which allow for a wide range of changes of the tolerance factor t12(T,d) as a function of oxygen content, perovskites AMO3 with M ions in the fixed oxidation state show much less flexibility. This flexibility is further reduced for the A3+M3+O3 perovskites like PrInO3 for which even a large change of the synthesis temperature has a minor effect on controlling the resulting t12(T) and the structural phase in comparison with A2+M4+O3 perovskites. The only parameter left for A3+M3+O3 materials allowing formation of various perovskites and hexagonal phases is the total pressure, which may significantly change t12(T,P). |
BibTeX:
@article{Baszczuk2015,
author = {Baszczuk, A. and Dabrowski, B. and Avdeev, M.},
title = {High temperature neutron diffraction studies of PrInO3 and the measures of perovskite structure distortion},
journal = {Dalt. Trans.},
year = {2015},
volume = {44},
number = {23},
pages = {10817--10827},
url = {http://xlink.rsc.org/?DOI=C4DT03881A},
doi = {10.1039/c4dt03881a}
}
|
| Bator G, Rok M, Sawka-Dobrowolska W, Sobczyk L, Zamponi M and Pawlukojć A (2015), "p-N,N′-tetraacetylodiaminodurene. The structure and vibrational spectra", Chem. Phys., Sep, 2015. Vol. 459, pp. 148-154. |
| Abstract: The crystal and molecular structure of p-N,N′-tetraacetylodiaminodurene (TADD) is reported based on the X-ray diffraction studies. The N-acetyl moieties are planar and all N-acetyl groups are perpendicular to the ring plane. Methyl groups both of acetyl moieties and of durene form a number of non-conventional hydrogen bonds with nitrogen and oxygen atoms. The vibrational spectra very well reflect the structure of molecules and their contacts. They are compared with calculated data by using various theoretical approaches. The neutron scattering spectra show two tunnel lines of low energy values (at ±0.9 and ±2.3 μeV at 4 K), which can be ascribed to methyl groups of N-acetyl moieties, which behave more freely than those attached to the phenyl ring. |
BibTeX:
@article{Bator2015,
author = {Bator, G. and Rok, M. and Sawka-Dobrowolska, W. and Sobczyk, L. and Zamponi, M. and Pawlukojć, A.},
title = {p-N,N′-tetraacetylodiaminodurene. The structure and vibrational spectra},
journal = {Chem. Phys.},
year = {2015},
volume = {459},
pages = {148--154},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0301010415002359},
doi = {10.1016/j.chemphys.2015.08.005}
}
|
| Bażela W, Baran S, Dyakonov V, Hoser A, Penc B, Zarzycki A and Szytuła A (2015), "Magnetic and neutron diffraction studies of magnetic properties of the nanoparticle RMno3 (R=Tb, Dy) manganites", In Springer Proc. Phys.. Vol. 167, pp. 245-253. |
BibTeX:
@inproceedings{Bazela2015,
author = {Bażela, W. and Baran, S. and Dyakonov, V. and Hoser, A. and Penc, B. and Zarzycki, A. and Szytuła, A.},
title = {Magnetic and neutron diffraction studies of magnetic properties of the nanoparticle rmno3 (R=Tb, Dy) manganites},
booktitle = {Springer Proc. Phys.},
year = {2015},
volume = {167},
pages = {245--253},
url = {https://link.springer.com/10.1007/978-3-319-18543-9_16},
doi = {10.1007/978-3-319-18543-9_16}
}
|
| Bouyrie Y, Candolfi C, Pailhès S, Koza MM, Malaman B, Dauscher A, Tobola J, Boisron O, Saviot L and Lenoir B (2015), "From crystal to glass-like thermal conductivity in crystalline minerals", Phys. Chem. Chem. Phys.. Vol. 17(30), pp. 19751-19758. |
| Abstract: Inelastic neutron scattering performed on powders and single crystals indicate that the glass-like thermal conductivity of tetrahedrite minerals originates from a strongly anharmonic low-energy vibrational mode related to the peculiar chemical environment of the Cu2 atoms. |
BibTeX:
@article{Bouyrie2015,
author = {Bouyrie, Y. and Candolfi, C. and Pailhès, S. and Koza, M. M. and Malaman, B. and Dauscher, A. and Tobola, J. and Boisron, O. and Saviot, L. and Lenoir, B.},
title = {From crystal to glass-like thermal conductivity in crystalline minerals},
journal = {Phys. Chem. Chem. Phys.},
year = {2015},
volume = {17},
number = {30},
pages = {19751--19758},
url = {http://xlink.rsc.org/?DOI=C5CP02900G},
doi = {10.1039/C5CP02900G}
}
|
| Buhot J, Méasson MA, Gallais Y, Cazayous M, Sacuto A, Bourdarot F, Raymond S, Lapertot G, Aoki D, Regnault LP, Ivanov A, Piekarz P, Parlinski K, Legut D, Homes CC, Lejay P and Lobo RP (2015), "Lattice dynamics of the heavy-fermion compound URu2Si2", Phys. Rev. B - Condens. Matter Mater. Phys., Jan, 2015. Vol. 91(3), pp. 035129. |
| Abstract: We report a comprehensive investigation of the lattice dynamics of URu2Si2 as a function of temperature using Raman scattering, optical conductivity, and inelastic neutron scattering measurements as well as theoretical ab initio calculations. The main effects on the optical phonon modes are related to Kondo physics. The B1g (Γ3 symmetry) phonon mode slightly softens below ∼100K, in connection with the previously reported softening of the elastic constant, C11-C12, of the same symmetry, both observations suggesting a B1g symmetry-breaking instability in the Kondo regime. Through optical conductivity, we detect clear signatures of strong electron-phonon coupling, with temperature-dependent spectral weight and Fano line shape of some phonon modes. Surprisingly, the line shapes of two phonon modes, Eu(1) and A2u(2), show opposite temperature dependencies. The A2u(2) mode loses its Fano shape below 150 K, whereas the Eu(1) mode acquires it below 100 K, in the Kondo crossover regime. This may point to momentum-dependent Kondo physics. By inelastic neutron-scattering measurements we have drawn the full dispersion of the phonon modes between 300 and 2 K. No remarkable temperature dependence has been obtained, including through the hidden order transition. Ab initio calculations with the spin-orbit coupling are in good agreement with the data except for a few low-energy branches with propagation in the (a,b) plane. |
BibTeX:
@article{Buhot2015,
author = {Buhot, J. and Méasson, M. A. and Gallais, Y. and Cazayous, M. and Sacuto, A. and Bourdarot, F. and Raymond, S. and Lapertot, G. and Aoki, D. and Regnault, L. P. and Ivanov, A. and Piekarz, P. and Parlinski, K. and Legut, D. and Homes, C. C. and Lejay, P. and Lobo, R. P.S.M.},
title = {Lattice dynamics of the heavy-fermion compound URu2Si2},
journal = {Phys. Rev. B - Condens. Matter Mater. Phys.},
year = {2015},
volume = {91},
number = {3},
pages = {035129},
url = {https://link.aps.org/doi/10.1103/PhysRevB.91.035129},
doi = {10.1103/PhysRevB.91.035129}
}
|
| Chatterji T, Kumar CMN and Wdowik UD (2015), "Anomalous temperature-induced volume contraction in GeTe", Phys. Rev. B., Feb, 2015. Vol. 91(5), pp. 054110. |
| Abstract: The recent surge of interest in phase-change materials GeTe, Ge2Sb2Te5, and related compounds motivated us to revisit the structural phase transition in GeTe in more detail than was done before. The rhombohedral-to-cubic ferroelectric phase transition in GeTe has been studied using high-resolution neutron powder diffraction on a spallation neutron source. We determined the temperature dependence of the structural parameters in a wide temperature range extending from 309 to 973 K. The results of our studies clearly show an anomalous volume contraction of 0.6% at the phase transition from the rhombohedral-to-cubic phase. In order to better understand the phase transition and the associated anomalous volume decrease in GeTe, we have performed phonon calculations based on the density functional theory. Results of the present investigations are also discussed with respect to the experimental data obtained for single crystals of GeTe. |
BibTeX:
@article{Chatterji2015,
author = {Chatterji, Tapan and Kumar, C. M. N. and Wdowik, Urszula D.},
title = {Anomalous temperature-induced volume contraction in GeTe},
journal = {Phys. Rev. B},
year = {2015},
volume = {91},
number = {5},
pages = {054110},
url = {https://link.aps.org/doi/10.1103/PhysRevB.91.054110},
doi = {10.1103/PhysRevB.91.054110}
}
|
| Drużbicki K, Mikuli E, Pałka N, Zalewski S and Ossowska-Chrus̈ciel M (2015), "Polymorphism of resorcinol explored by complementary vibrational spectroscopy (FT-RS, THz-TDS, INS) and first-principles solid-state computations (plane-wave DFT)", J. Phys. Chem. B. Vol. 119(4), pp. 1681-1695. |
| Abstract: The polymorphism of resorcinol has been complementary studied by combining Raman, time-domain terahertz, and inelastic neutron scattering spectroscopy with modern solid-state density functional theory (DFT) calculations. The spectral differences, emerging from the temperature-induced structural phase transition, have been successfully interpreted with an emphasis on the low-wavenumber range. The given interpretation is based on the plane-wave DFT computations, providing an excellent overall reproduction of both wavenumbers and intensities and revealing the source of the observed spectral differences. The performance of the generalized gradient approximation (GGA) functionals in prediction of the structural parameters and the vibrational spectra of the normal-pressure polymorphs of resorcinol has been extensively examined. The results show that the standard Perdew, Burke, and Ernzerhof (PBE) approach along with its "hard" revised form tends to be superior if compared to the "soft" GGA approximation. (Graph Presented) |
BibTeX:
@article{Druzbicki2015,
author = {Druzbicki, K. and Mikuli, E. and Pałka, N. and Zalewski, S. and Ossowska-Chrus̈ciel, M.D.},
title = {Polymorphism of resorcinol explored by complementary vibrational spectroscopy (FT-RS, THz-TDS, INS) and first-principles solid-state computations (plane-wave DFT)},
journal = {J. Phys. Chem. B},
year = {2015},
volume = {119},
number = {4},
pages = {1681--1695},
doi = {10.1021/jp507241j}
}
|
| Golovchak R, Lucas P, Oelgoetz J, Kovalskiy A, York-Winegar J, Saiyasombat C, Shpotyuk O, Feygenson M, Neuefeind J and Jain H (2015), "Medium range order and structural relaxation in As-Se network glasses through FSDP analysis", Mater. Chem. Phys.. Vol. 153, pp. 432-442. |
| Abstract: Synchrotron X-ray diffraction and neutron scattering studies are performed on As-Se glasses in two states: as-prepared (rejuvenated) and aged for ∼27 years. The first sharp diffraction peak (FSDP) obtained from the structure factor data as a function of composition and temperature indicates that the cooperative processes that are responsible for structural relaxation do not affect FSDP. The results are correlated with the composition dependence of the complex heat capacity of the glasses and concentration of different structural fragments in the glass network. The comparison of structural information shows that density fluctuations, which were thought previously to have a significant contribution to FSDP, have much smaller effect than the cation-cation correlations, presence of ordered structural fragments or cage molecules. |
BibTeX:
@article{Golovchak2015,
author = {Golovchak, R. and Lucas, P. and Oelgoetz, J. and Kovalskiy, A. and York-Winegar, J. and Saiyasombat, Ch. and Shpotyuk, O. and Feygenson, M. and Neuefeind, J. and Jain, H.},
title = {Medium range order and structural relaxation in As-Se network glasses through FSDP analysis},
journal = {Mater. Chem. Phys.},
year = {2015},
volume = {153},
pages = {432--442},
doi = {10.1016/j.matchemphys.2015.01.037}
}
|
| Gosecka M and Gosecki M (2015), "Characterization methods of polymer core–shell particles", Colloid Polym. Sci.. Vol. 293(10), pp. 2719-2740. |
| Abstract: The design and synthesis of various polymer core–shell particles result from their distinct characteristics, which combine the properties of two or more components into one material. Many accessible synthetic strategies for obtaining polymer core–shell particles lead to the formation of particles for which the internal morphology differs from the ideal core–shell structure. Understanding the precise morphology characteristics is important for mechanistic studies of particle formation, which ultimately results in the design of particles for specific structures and properties. The detailed characteristics of complex polymer particle structures are complicated and require more than one method. This review focuses on imaging methods such as transmission electron microscopy (TEM), cryo-TEM, scanning transmission electron microscopy (STEM) and confocal fluorescence microscopy that reveal the radial redistribution of the components and methods for the quantitative analysis of individual phases (core, shell and interfacial layer), such as small-angle X-ray scattering (SAXS), small-angle neutron scattering (SANS), differential scanning calorimetry (DSC) and nuclear magnetic resonance (NMR). Methods that can determine the surface composition and makeup of the character of interfacial layer (gradient or containing small domains, etc.) were also reviewed. |
BibTeX:
@article{Gosecka2015,
author = {Gosecka, M. and Gosecki, M.},
title = {Characterization methods of polymer core–shell particles},
journal = {Colloid Polym. Sci.},
year = {2015},
volume = {293},
number = {10},
pages = {2719--2740},
doi = {10.1007/s00396-015-3728-z}
}
|
| Gromadzki D, Rychter P, Uchman M, Momekova D, Marcinkowski A, Koseva N, El Fray M and Maric M (2015), "Multifunctional amphiphilic nanoparticles featuring (bio)degradable core and dual-responsive shell as biomedical platforms for controlled release", Macromol. Chem. Phys.. Vol. 216(23), pp. 2287-2301. |
| Abstract: Multifunctional polymeric platforms combining (bio)degradable and biocompatible, temperature and pH-sensitive entities hold great promise as nanocarriers for targeted drug and gene delivery, and tissue engineering. In this work, preparation and characterization of surfactant-free polyester nanoparticles (NPs) from biobased polyesters poly(butylene sebacate) (PBSE) and poly(butylene sebacate-co-butylene dilinoleate)s (PBSE/PBDL) using nanoprecipitation is reported. This strategy leads to spherical nanosized particles with sizes narrowly distributed in a range of 30-200 nm which is appropriate for internalization by a variety of cells. The effect of molecular parameters and type of solvent used in the nanoprecipitation protocol on the size and shape of produced polyester nanocolloids and their in vitro degradation in PBS solution at 37 °C is elucidated by quasi-elastic light scattering (QELS), atomic force microscopy (AFM), transmission electron microscopy (TEM), and size-exclusion chromatography (SEC) techniques. A dense cationic brush layer (≈ 20 nm) of stimuli-responsive and biocompatible poly(2-dimethylaminoethyl methacrylate-co-acrylonitrile) is grafted on the surface of PBSE/PBDL NPs through "grafting onto" (arm first) coupling chemistry. Nanoprecipitation and "grafting onto" strategy affords bio(degradable) and stimuli-sensitive core-shell nanoparticles. Well-defined spherical and biocompatible nanostructures are characterized by dynamic and static light scattering, small-angle neutron scattering, atomic force microscopy, and transmission electron microscopy. The solution properties, stability, and degradation of nanoparticles in aqueous and phosphate buffer saline media have been investigated. |
BibTeX:
@article{Gromadzki2015,
author = {Gromadzki, D. and Rychter, P. and Uchman, M. and Momekova, D. and Marcinkowski, A. and Koseva, N.S. and El Fray, M. and Maric, M.},
title = {Multifunctional amphiphilic nanoparticles featuring (bio)degradable core and dual-responsive shell as biomedical platforms for controlled release},
journal = {Macromol. Chem. Phys.},
year = {2015},
volume = {216},
number = {23},
pages = {2287--2301},
doi = {10.1002/macp.201500235}
}
|
| Iwanowska J, Swiderski L, Krakowski T, Moszynski M, Szczesniak T and Pausch G (2015), "The time-of-flight method for characterizing the neutron response of liquid organic scintillators", Nucl. Instruments Methods Phys. Res. Sect. A Accel. Spectrometers, Detect. Assoc. Equip.. Vol. 781, pp. 44-49. |
| Abstract: The purpose of this work is to present a measurement method for determining the neutron responses of various liquid organic scintillators using a time-of-flight technique in conjunction with a D-T neutron generator. The method is based on fast-neutron scattering on protons in a liquid-scintillator medium and on the acquisition of the neutron response of the medium as a function of the proton-recoil energy. This method can be applied to all scintillators that utilize fast-neutron elastic scattering. |
BibTeX:
@article{Iwanowska2015,
author = {Iwanowska, J. and Swiderski, L. and Krakowski, T. and Moszynski, M. and Szczesniak, T. and Pausch, G.},
title = {The time-of-flight method for characterizing the neutron response of liquid organic scintillators},
journal = {Nucl. Instruments Methods Phys. Res. Sect. A Accel. Spectrometers, Detect. Assoc. Equip.},
year = {2015},
volume = {781},
pages = {44--49},
doi = {10.1016/j.nima.2015.01.051}
}
|
| Jagło G, Mȩdala M and Wdowik U (2015), "Ab initio phonon dynamics in the layered ternary diselenide KNi2Se2", Phys. Lett. A., Jan, 2015. Vol. 379(3), pp. 183-186. |
| Abstract: Dynamical properties of KNi2Se2 lattice are investigated within density functional theory and the approximation of harmonic phonons. Partial phonon densities of states indicate that Ni and Se vibrations span the entire spectral range extending to 27 meV, whereas K vibrations are limited to 11-18 meV. It is shown that inelastic neutron scattering spectra reflect the dynamics of Ni atoms within [Ni2Se2] blocks and the high-energy Eg mode is hardly observed in the Raman spectra due to its low intensity. The electronic contribution to the heat capacity of 47 mJmol-1K-2 is estimated at very low temperatures. |
BibTeX:
@article{Jago2015,
author = {Jagło, G. and Mȩdala, M. and Wdowik, U.D.},
title = {Ab initio phonon dynamics in the layered ternary diselenide KNi2Se2},
journal = {Phys. Lett. A},
year = {2015},
volume = {379},
number = {3},
pages = {183--186},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0375960114011177},
doi = {10.1016/j.physleta.2014.11.010}
}
|
| Jiang K, Zhang C, Guttula D, Liu F, Van Kan J, Lavelle C, Kubiak K, Malabirade A, Lapp A, Arluison V, Arluison V and Van Der Maarel J (2015), "Effects of Hfq on the conformation and compaction of DNA", Nucleic Acids Res.. Vol. 43(8), pp. 4332-4341. |
| Abstract: Hfq is a bacterial pleiotropic regulator that mediates several aspects of nucleic acids metabolism. The protein notably influences translation and turnover of cellular RNAs. Although most previous contributions concentrated on Hfq's interaction with RNA, its association to DNA has also been observed in vitro and in vivo. Here, we focus on DNA-compacting properties of Hfq. Various experimental technologies, including fluorescence microscopy imaging of single DNA molecules confined inside nanofluidic channels, atomic force microscopy and small angle neutron scattering have been used to follow the assembly of Hfq on DNA. Our results show that Hfq forms a nucleoprotein complex, changes the mechanical properties of the double helix and compacts DNA into a condensed form. We propose a compaction mechanism based on protein-mediated bridging of DNA segments. The propensity for bridging is presumably related to multi-arm functionality of the Hfq hexamer, resulting from binding of the C-terminal domains to the duplex. Results are discussed in regard to previous results obtained for H-NS, with important implications for protein binding related gene regulation. |
BibTeX:
@article{Jiang2015,
author = {Jiang, K. and Zhang, C. and Guttula, D. and Liu, F. and Van Kan, J.A. and Lavelle, C. and Kubiak, K. and Malabirade, A. and Lapp, A. and Arluison, V. and Arluison, V. and Van Der Maarel, J.R.C.},
title = {Effects of Hfq on the conformation and compaction of DNA},
journal = {Nucleic Acids Res.},
year = {2015},
volume = {43},
number = {8},
pages = {4332--4341},
doi = {10.1093/nar/gkv268}
}
|
| Kiwilsza A, Pajzderska A, Gonzalez M, Mielcarek J and Wasicki J (2015), "QENS and NMR Study of Water Dynamics in SBA-15 with a Low Water Content", J. Phys. Chem. C. Vol. 119(29), pp. 16578-16586. |
| Abstract: In this study, motions performed by water
molecules adsorbed on the silica surface of SBA-15 material with
6.1% of water content (15% of pore filling) were investigated using
NMR and Quasielastic Neutron Scattering (QENS) techniques. The
results show no sign of translational diffusion of water, but two
types of stochastic localized motions were identified, and both
described using a model of proton jumps between two sites. For both
motions, the characteristic jump distances and correlation times, as
well as activation energies, have been extracted and found to differ
significantly. On this basis, the faster motion was ascribed to
jumps of water molecules between neighboring positions (d = 2.5 Å, τ
= 4 ps at 300 K, and E |
BibTeX:
@article{Kiwilsza2015,
author = {Kiwilsza, A. and Pajzderska, A. and Gonzalez, M.A. and Mielcarek, J. and Wasicki, J.},
title = {QENS and NMR Study of Water Dynamics in SBA-15 with a Low Water Content},
journal = {J. Phys. Chem. C},
year = {2015},
volume = {119},
number = {29},
pages = {16578--16586},
doi = {10.1021/acs.jpcc.5b02672}
}
|
| Kulka A, Braun A, Huang T-W, Wolska A, Klepka MT, Szewczyk A, Baster D, Zajac W, Świerczek K and Molenda J (2015), "Evidence for Al doping in lithium sublattice of LiFePO4", Solid State Ionics., Feb, 2015. Vol. 270, pp. 33-38. |
| Abstract: In this work, we applied various measurement techniques in order to evaluate the possibility of the introduction of Al and its actual level at Li site in LiFePO4 positive electrode material for Li-ion batteries. Rietveld refinement of neutron diffraction data indicated that Al is incorporated into Li site, however, in lower amount than expected, and that lithium content is substantially depressed. The observed trends were qualitatively supported by results of ICP OES analysis. In addition, the oxygen content in Li1-3xAlxFePO4 was found to decrease with Al doping. The introduction of relatively small amount of dopant could be an effective route to produce single-phase, highly lithium-deficient lithium iron phosphate. Spectroscopic methods (EXAFS and XANES) do not allow to unambiguously confirm the substitution; nevertheless, all the obtained results are compatible with the substitution taking place. Interestingly, electrochemical studies indicated improvement of the performance of a LiFePO4 cathode material upon partial substitution of lithium by aluminum, possibly as the effect of increase of concentration of lithium vacancies. |
BibTeX:
@article{Kulka2015,
author = {Kulka, Andrzej and Braun, Artur and Huang, Tzu-Wen and Wolska, Anna and Klepka, Marcin T. and Szewczyk, Andrzej and Baster, Dominika and Zajac, Wojciech and Świerczek, Konrad and Molenda, Janina},
title = {Evidence for Al doping in lithium sublattice of LiFePO4},
journal = {Solid State Ionics},
year = {2015},
volume = {270},
pages = {33--38},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167273814005128},
doi = {10.1016/j.ssi.2014.12.004}
}
|
| Leszczynska M, Borowska-Centkowska A, Malys M, Dygas J, Krok F, Wrobel W and Abrahams I (2015), "The double rare-earth substituted bismuth oxide system Bi3Y1−xYbxO6", Solid State Ionics., Jan, 2015. Vol. 269, pp. 37-43. |
| Abstract: Structure and electrical conductivity in the double rare-earth substituted system Bi3Y1-xYbxO6 (0.00 ≤ x ≤ 1.00) is discussed. Structural characterization, by X-ray and neutron powder diffraction, confirms a full δ-Bi2O3 type solid solution. This structure is maintained up to 850 °C, with no visible evidence for phase separation over the timescale of the diffraction experiments. Small compositional changes in oxide ion distribution are observed, with Yb rich compositions favoring a more centralized oxide ion distribution in the tetrahedral cavities. Electrical characterization, by a.c. impedance spectroscopy, reveals the system to be highly conducting, with measurements of transference number indicating this conductivity to be almost purely ionic at temperatures above ca. 600 °C. At lower temperatures, transference number decreases with increasing ytterbium content. Maxima in activation energy and conductivity pre-exponential factor at high temperatures are observed at x = 0.50 and are discussed in terms of changes in configurational entropy. This behaviour resembles the "mixed alkali effect" frequently observed in glasses. However, in the present case there is no corresponding minimum in conductivity and the effect is associated with the immobile sublattice. |
BibTeX:
@article{Leszczynska2015,
author = {Leszczynska, M. and Borowska-Centkowska, A. and Malys, M. and Dygas, J.R. and Krok, F. and Wrobel, W. and Abrahams, I.},
title = {The double rare-earth substituted bismuth oxide system Bi3Y1−xYbxO6},
journal = {Solid State Ionics},
year = {2015},
volume = {269},
pages = {37--43},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167273814004603},
doi = {10.1016/j.ssi.2014.11.012}
}
|
| Lind T, Darré L, Domene C, Urbanczyk-Lipkowska Z, Cárdenas M and Wacklin H (2015), "Antimicrobial peptide dendrimer interacts with phosphocholine membranes in a fluidity dependent manner: A neutron reflection study combined with molecular dynamics simulations", Biochim. Biophys. Acta - Biomembr.. Vol. 1848(10), pp. 2075-2084. |
| Abstract: The interaction mechanism of a novel amphiphilic antimicrobial peptide dendrimer, BALY, with model lipid bilayers was explored through a combination of neutron reflection and molecular dynamics simulations. 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1,2-dipalmitoyl-sn-glycero-3-phos-phocholine (DPPC) lipid bilayers were examined at room temperature to extract information on the interaction of BALY with fluid and gel phases, respectively. Furthermore, a 1:4 mixture of POPC and DPPC was used as a model of a phase-separated membrane. Upon interaction with fluid membranes, BALY inserted in the distal leaflet and caused thinning and disordering of the headgroups. Membrane thinning and expansion of the lipid cross-sectional area were observed for gel phase membranes, also with limited insertion to the distal leaflet. However, dendrimer insertion through the entire lipid tail region was observed upon crossing the lipid phase transition temperature of DPPC and in phase separated membranes. The results show clear differences in the interaction mechanism of the dendrimer depending on the lipid membrane fluidity, and suggest a role for lipid phase separation in promoting its antimicrobial activity. |
BibTeX:
@article{Lind2015,
author = {Lind, T.K. and Darré, L. and Domene, C. and Urbanczyk-Lipkowska, Z. and Cárdenas, M. and Wacklin, H.P.},
title = {Antimicrobial peptide dendrimer interacts with phosphocholine membranes in a fluidity dependent manner: A neutron reflection study combined with molecular dynamics simulations},
journal = {Biochim. Biophys. Acta - Biomembr.},
year = {2015},
volume = {1848},
number = {10},
pages = {2075--2084},
doi = {10.1016/j.bbamem.2015.05.015}
}
|
| Natkaniec I, Sheka E, Drużbicki K, Hołderna-Natkaniec K, Gubin S, Buslaeva E and Tkachev S (2015), "Computationally Supported Neutron Scattering Study of Parent and Chemically Reduced Graphene Oxide", J. Phys. Chem. C. Vol. 119(32), pp. 18650-18662. |
| Abstract: Synthetic graphene oxide (GO) as well as the product of its reducing performed in the regime of hydrogenolysis (rGO) were studied by both elastic and inelastic neutron scattering at low and room temperature conditions. The neutron diffraction patterns were analyzed to confirm stacking structures of both species consisting of 2-3 and ∼7 layers of microsize lateral dimension and the interlayer distances of 7 and 3.5 Å, respectively. The inelastic incoherent neutron scattering spectra were analyzed in the frame of the computationally supported one-phonon amplitude-weighted density of vibrational states G(ω) approximation. Calculations of G(ω) spectra were performed in the framework of semilocal density functional theory. The computational models were adjusted to the atom mass content of both GO and rGO species. The presented study has revealed the retained water in the freshly made GO, corresponding to the relatively low humidity, which further reacts with the oxygen-containing groups at the GO basal planes. The reaction results in the formation of hydroxyls chemically bound to the GO core in the course of the prolong storage of the product under ambient conditions. The analysis of the rGO G(ω) spectrum has disclosed the chemical composition of its circumference attributing the latter to sets of CH units with a minor presence of atomic oxygen. |
BibTeX:
@article{Natkaniec2015,
author = {Natkaniec, I. and Sheka, E.F. and Druzbicki, K. and Hołderna-Natkaniec, K. and Gubin, S.P. and Buslaeva, E.Y. and Tkachev, S.V.},
title = {Computationally Supported Neutron Scattering Study of Parent and Chemically Reduced Graphene Oxide},
journal = {J. Phys. Chem. C},
year = {2015},
volume = {119},
number = {32},
pages = {18650--18662},
doi = {10.1021/acs.jpcc.5b01676}
}
|
| Pajzderska A, Drużbicki K, Kiwilsza A, Gonzalez M, Jarek M, Mielcarek J and Wąsicki J (2015), "On the relaxation dynamics in active pharmaceutical ingredients: Solid-state 1H NMR, quasi-elastic neutron scattering and periodic DFT study of acebutolol hydrochloride", RSC Adv.. Vol. 5(71), pp. 57502-57514. |
| Abstract: The molecular dynamics of a cardioselective beta-blocker with intrinsic sympathomimetic activity-acebutolol hydrochloride, was investigated by employing spin-lattice relaxation 1H nuclear magnetic resonance (NMR) and quasielastic neutron scattering (QENS) experiments along with periodic density functional theory (DFT) computations. The relaxation experiments reveal the presence of four dynamic processes, further assigned to the methyl groups reorientations. The analyzed motions were characterized in terms of their activation barriers and correlation times, while their assignment was supported by theoretical computations. The earlier reported crystallographic structure reveals intriguing features in the large-size unit-cell, defined by eight molecular units. By combining solid-state DFT calculations with the intermolecular interactions analysis (Hirshfeld Surface; Reduced Density Gradient), the nature of the stabilizing crystal forces has been revealed, emphasizing the role of moderate-strength (N-H⋯O; O-H⋯Cl; N-H⋯Cl) and weak (C-H⋯O) hydrogen-bond contacts. The theoretical computations provide clear support for the assignment of particular motions and interpretation of the experimental data as showing a competing influence of both internal-structure and intermolecular factors on their activation barriers. The highest energy barriers were assigned to the acetyl-related methyl rotors, the intermediate ones are due to the isopropyl part, while the most-dynamic methyl groups are assigned to the alkyl chain. Inclusion of crystallographic forces via calculations in periodic boundary conditions was found to be essential for a proper understanding of both the conformational and dynamic properties of the system under interest, as it could not be achieved with molecular modeling. Therefore, the performance of several semi-local exchange-correlation functional approximations was critically examined, revealing a clear tendency in favor of the 'soft' and dispersion-corrected schemes for estimation of the rotational barriers in pharmaceutical solids. |
BibTeX:
@article{Pajzderska2015,
author = {Pajzderska, A. and Druzbicki, K. and Kiwilsza, A. and Gonzalez, M.A. and Jarek, M. and Mielcarek, J. and Wasicki, J.},
title = {On the relaxation dynamics in active pharmaceutical ingredients: Solid-state 1H NMR, quasi-elastic neutron scattering and periodic DFT study of acebutolol hydrochloride},
journal = {RSC Adv.},
year = {2015},
volume = {5},
number = {71},
pages = {57502--57514},
doi = {10.1039/c5ra08937a}
}
|
| Pinkowicz D, Southerland H, Avendaño C, Prosvirin A, Sanders C, Wernsdorfer W, Pedersen K, Dreiser J, Clérac R, Nehrkorn J, Holldack K and Dunbar K (2015), "Cyanide Single-Molecule Magnets Exhibiting Solvent Dependent Reversible "on" and "off" Exchange Bias Behavior", J. Am. Chem. Soc.. Vol. 137(45), pp. 14406-14422. |
| Abstract: The syntheses, structures, and magnetic properties of four new complex salts, (PPN)[MnIII(salphen)(MeOH)]2[MIII(CN)6]textperiodcentered7MeOH (Mn2Mtextperiodcentered7MeOH) (M = Fe, Ru, Os and Co; PPN+ = bis(triphenylphosphoranylidene)ammonium cation; H2salphen = N,N′-bis(salicylidene)-1,2-diaminobenzene), and a mixed metal Co/Os analogue (PPN)[MnIII(salphen)(MeOH)]2[CoIII0.92OsIII0.08(CN)6]textperiodcentered7MeOH were undertaken. It was found that all compounds exhibit switchable single-molecule magnet (SMM) and exchange-bias behavior depending on the interstitial methanol content. The pristine (PPN)[Mn(salphen)(MeOH)]2[Os(CN)6]textperiodcentered7MeOH (Mn2Ostextperiodcentered7MeOH) behaves as an SMM with an effective barrier for the magnetization reversal, (Ueff/kB), of 17.1 K. Upon desolvation, Mn2Os exhibits an increase of Ueff/kB to 42.0 K and an opening of the hysteresis loop observable at 1.8 K. Mn2Ostextperiodcentered7MeOH shows also exchange-bias behavior with magnetic hysteresis loops exhibiting a shift in the quantum tunneling to 0.25 T from zero-field. The FeIII and RuIII analogues were prepared as reference compounds for assessing the effect of the 5d versus 4d and 3d metal ions on the SMM properties. These compounds are also SMMs and exhibit similar effects but with lower energy barriers. These findings underscore the importance of introducing heavy transition elements into SMMs to improve their slow relaxation of the magnetization properties. The (PPN)[MnIII(salphen)(MeOH)]2[CoIII(CN)6]textperiodcentered7MeOH (Mn2Cotextperiodcentered7MeOH) analogue with a diamagnetic CoIII central atom and the mixed Co/Os (PPN)[MnIII(salphen)(MeOH)]2[CoIII0.92OsIII0.08(CN)6]textperiodcentered7MeOH (Mn2Co/Ostextperiodcentered7MeOH) "magnetically diluted" system with a 9:1 Co/Os metal ratio were prepared in order to further probe the nature of the energy barrier increase upon desolvation of Mn2Os. In addition, inelastic neutron scattering and frequency-domain Fourier-transform THz electron paramagnetic resonance spectra obtained on Mn2Ostextperiodcentered7MeOH and Mn2Os in combination with the magnetic data revealed the presence of anisotropic exchange interactions between MnIII and OsIII ions. |
BibTeX:
@article{Pinkowicz2015,
author = {Pinkowicz, D. and Southerland, H.I. and Avendaño, C. and Prosvirin, A. and Sanders, C. and Wernsdorfer, W. and Pedersen, K.S. and Dreiser, J. and Clérac, R. and Nehrkorn, J. and Holldack, K. and Dunbar, K.R.},
title = {Cyanide Single-Molecule Magnets Exhibiting Solvent Dependent Reversible "on" and "off" Exchange Bias Behavior},
journal = {J. Am. Chem. Soc.},
year = {2015},
volume = {137},
number = {45},
pages = {14406--14422},
doi = {10.1021/jacs.5b09378}
}
|
| Porter DG, Cemal E, Voneshen DJ, Refson K, Gutmann MJ, Bombardi A, Boothroyd AT, Krzton-Maziopa A, Pomjakushina E, Conder K and Goff JP (2015), "Two-dimensional Cs-vacancy superstructure in iron-based superconductor Cs0.8Fe1.6Se2", Phys. Rev. B - Condens. Matter Mater. Phys., Apr, 2015. Vol. 91(14), pp. 144114. |
| Abstract: Single crystal neutron diffraction is combined with synchrotron x-ray scattering to identify the different superlattice phases present in Cs0.8Fe1.6Se2. A combination of single crystal refinements and first principles modeling are used to provide structural solutions for the √5 x √5 and √2 x √2 superlattice phases. The √5 x √5 superlattice structure is predominantly composed of ordered Fe vacancies and Fe distortions, whereas the √2 x √2 superlattice is composed of ordered Cs vacancies. The Cs vacancies only order within the plane, causing Bragg rods in reciprocal space. By mapping x-ray diffraction measurements with narrow spatial resolution over the surface of the sample, the structural domain pattern was determined, consistent with the notion of a majority antiferromagnetic √5 x √5 phase and a superconducting √2 x √2 phase. |
BibTeX:
@article{Porter2015,
author = {Porter, D. G. and Cemal, E. and Voneshen, D. J. and Refson, K. and Gutmann, M. J. and Bombardi, A. and Boothroyd, A. T. and Krzton-Maziopa, A. and Pomjakushina, E. and Conder, K. and Goff, J. P.},
title = {Two-dimensional Cs-vacancy superstructure in iron-based superconductor Cs0.8Fe1.6Se2},
journal = {Phys. Rev. B - Condens. Matter Mater. Phys.},
year = {2015},
volume = {91},
number = {14},
pages = {144114},
url = {https://link.aps.org/doi/10.1103/PhysRevB.91.144114},
doi = {10.1103/PhysRevB.91.144114}
}
|
| Prylutskyy YI, Cherepanov VV, Evstigneev MP, Kyzyma OA, Petrenko VI, Styopkin VI, Bulavin LA, Davidenko NA, Wyrzykowski D, Woziwodzka A, Piosik J, Kaźmierkiewicz R and Ritter U (2015), "Structural self-organization of C60 and cisplatin in physiological solution", Phys. Chem. Chem. Phys.. Vol. 17(39), pp. 26084-26092. |
| Abstract: The specific features of structural self-organization of C 60 fullerene and antitumor drug cisplatin (Cis) in physiological solution (0.9% NaCl) have been investigated. |
BibTeX:
@article{Prylutskyy2015,
author = {Prylutskyy, Yu I. and Cherepanov, V. V. and Evstigneev, M. P. and Kyzyma, O. A. and Petrenko, V. I. and Styopkin, V. I. and Bulavin, L. A. and Davidenko, N. A. and Wyrzykowski, D. and Woziwodzka, A. and Piosik, J. and Kaźmierkiewicz, R. and Ritter, U.},
title = {Structural self-organization of C60 and cisplatin in physiological solution},
journal = {Phys. Chem. Chem. Phys.},
year = {2015},
volume = {17},
number = {39},
pages = {26084--26092},
url = {http://xlink.rsc.org/?DOI=C5CP02688A},
doi = {10.1039/C5CP02688A}
}
|
| Rećko K, Dobrzyński L, Waliszewski J and Szymański K (2015), "Magnetic anisotropy in the incommensurate ScFe4Al8 system", J. Magn. Magn. Mater., Aug, 2015. Vol. 388, pp. 82-89. |
| Abstract: Neutron scattering and magnetization data are used for estimation of the spin ordering in ScFe4Al8. Results of experimental measurements are compared with the ground state configurations obtained by simulated annealing algorithms. The origins of the magnetocrystalline anisotropy of the scandium intermetallic alloy and the conditions of the coexistence of two different magnetic modulations as a function of the exchange integrals are discussed. The influence of the dipolar interactions for the noncollinearity and incommensurability in ScFe4Al8 was determined. |
BibTeX:
@article{Recko2015,
author = {Rećko, K. and Dobrzyński, L. and Waliszewski, J. and Szymański, K.},
title = {Magnetic anisotropy in the incommensurate ScFe4Al8 system},
journal = {J. Magn. Magn. Mater.},
year = {2015},
volume = {388},
pages = {82--89},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0304885315300020},
doi = {10.1016/j.jmmm.2015.03.096}
}
|
| Rećko K, Dobrzyński L, Waliszewski J and Szymański K (2015), "Reconstruction of the exchange integrals map of ScFe4Al8 magnetic structure", Acta Phys. Pol. A. Vol. 127(2), pp. 424-426. |
| Abstract: The influence of the dipolar as well as crystal field interaction as the main reasons of the noncollinearity and incommensurability of the 3d-3d-3p alloy belonging to ThMn12 family is investigated. Available data on the single crystal neutron scattering experiments for ScFe4Al8 compound are discussed. The values and directions of the spin ordering found by magnetic diffraction are compared to that one derived from ground state configurations obtained by a simulated annealing algorithm. |
BibTeX:
@article{Recko2015a,
author = {Rećko, K. and Dobrzyński, L. and Waliszewski, J. and Szymański, K.},
title = {Reconstruction of the exchange integrals map of ScFe4Al8 magnetic structure},
journal = {Acta Phys. Pol. A},
year = {2015},
volume = {127},
number = {2},
pages = {424--426},
doi = {10.12693/APhysPolA.127.424}
}
|
| Rećko K, Wykowska U, Olszewski W, André G, Milczarek JJ, Satua D, Biernacka M, Kalska-Szostko B, Waliszewski J and Szymanski K (2015), "Synthesis and magnetic properties of the multiferroic GaFeO3 of orthorhombic and hexagonal symmetry", J. Optoelectron. Adv. Mater.. Vol. 17(7-8), pp. 1173-1178. |
| Abstract: In the past decade research on the multiferroic nature of gallium iron oxide has been of interest for several reasons. GaFeO3 (GFO) has been intensively studied for its potential applications as a magnetoelectric material [1]. Such a system can be used for switching its electric state vs. magnetic state and vice versa. Moreover GFO seems to be promising memory media which allow a simultaneous reading and writing of data and will be useful in data storage as well [2]. The physical properties especially magnetism in GaFeO3, depend strongly on the method of preparation. This work reports the preparation of gallium iron oxide by the sol-gel route (SG) and its characterization made by X-ray together with neutron diffraction techniques. The low-and room temperature 57Fe Mössbauer spectroscopy measurements were collected to complement the phase characteristics with relative fractions of the orthorhombic end/or hexagonal phases. |
BibTeX:
@article{Reko2015,
author = {Reko, K. and Wykowska, U. and Olszewski, W. and André, G. and Milczarek, J. J. and Satua, D. and Biernacka, M. and Kalska-Szostko, B. and Waliszewski, J. and Szymanski, K.},
title = {Synthesis and magnetic properties of the multiferroic GaFeO3 of orthorhombic and hexagonal symmetry},
journal = {J. Optoelectron. Adv. Mater.},
year = {2015},
volume = {17},
number = {7-8},
pages = {1173--1178}
}
|
| Remhof A, Yan Y, Embs JP, Sakai VG, Nale A, de Jongh P, Łodziana Z and Züttel A (2015), "Rotational disorder in lithium borohydride", EPJ Web Conf., Jan, 2015. Vol. 83, pp. 02014. |
| Abstract: LiBH4 has been discussed as a promising hydrogen storage material and as a solid-state electrolyte in lithium-ion batteries. It contains 18.5 wt% hydrogen and undergoes a structural phase transition at 381 K which is associated with a large increase in rotational disorder of the [BH4]- anion and the increase of [Li]+ conductivity by three orders of magnitude. We investigated the [BH4]- anion dynamic in bulk LiBH4, in LiBH4-LiI solid solutions and in nano-confined LiBH4 by quasielastic neutron scattering, complemented by DFT calculations. In all cases the H-dynamics is dominated by thermally activated rotational jumps of the [BH4]- anion in the terahertz range. The addition of LiI as well as nano-confinement favours the disordered high temperature phase and lowers the phase transition below room temperatures. The results are discussed on the basis of first principles calculations and in relation to ionic conductivity of [Li]+. |
BibTeX:
@article{Remhof2015,
author = {Remhof, Arndt and Yan, Yigang and Embs, Jan Peter and Sakai, Victoria Garcia and Nale, Angeloclaudio and de Jongh, Petra and Łodziana, Zbigniew and Züttel, Andreas},
editor = {Frick, B. and Koza, M. M. and Boehm, M. and Mutka, H.},
title = {Rotational disorder in lithium borohydride},
journal = {EPJ Web Conf.},
year = {2015},
volume = {83},
pages = {02014},
url = {http://www.epj-conferences.org/10.1051/epjconf/20158302014},
doi = {10.1051/epjconf/20158302014}
}
|
| Rusinek D, Czub J, Niewolski J, Gondek, Gajewska M, Takasaki A, Hoser A and Zywczak A (2015), "Structural phase transitions in the Ti45Zr38Ni17-xFex nano-alloys and their deuterides", J. Alloys Compd., Oct, 2015. Vol. 646, pp. 90-95. |
| Abstract: Abstract The mechanically alloyed Ti-Zr-Ni materials are extensively studied due to their promising properties concerning biomedical, electronic or hydrogen related applications (for example the gaseous hydrogen storage and the MNiH batteries). In this paper we address the very crucial issue of the structural properties and transformations of the amorphous and quasicrystalline Ti45Zr38Ni17-xFex (x = 0, 4, 8) and their hydrides. According to the neutron diffraction results, the transformation of the amorphous Ti45Zr38Ni17 phase into the icosahedral quasicrystalline state (the i-phase) is quasi-continuous and starts at the relatively low temperature of 300°C. At 500°C the i-phase is well-developed. At higher temperatures the i-phase transforms into the approximant w-phase and eventually into the cubic phase (the c-phase). Interestingly, the deuterided i-phase exhibits completely different thermal evolution. Namely, this phase decomposes into the simple intermetallic compounds above 625°C. What is worth-mentioning is that the release of deuterium is strictly related to that structural decomposition. The possibility of hydrogenation of the amorphous Ti45Zr38Ni17-xFex phases with maintaining the amorphous nature of the alloys is the other extremely important field of our interest. We established a processing route to meet our goal. Finally, we show that introducing deuterium triggers an exciting phase transition from the deuterided amorphous phase into the unknown before, partially disordered, quasicrystalline-like phase (the glassy quasicrystal) without releasing of deuterium. |
BibTeX:
@article{Rusinek2015,
author = {Rusinek, D. and Czub, J. and Niewolski, J. and Gondek and Gajewska, M. and Takasaki, A. and Hoser, A. and Zywczak, A.},
title = {Structural phase transitions in the Ti45Zr38Ni17-xFex nano-alloys and their deuterides},
journal = {J. Alloys Compd.},
year = {2015},
volume = {646},
pages = {90--95},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838815301389},
doi = {10.1016/j.jallcom.2015.06.023}
}
|
| Sosnowska I (2015), "The birth of time-of-flight (TOF) neutron powder diffraction at pulsed neutron source (invited)", Cryst. Res. Technol.. Vol. 50(9-10), pp. 705-715. |
| Abstract: Behind every improvement there is a story. The early history of the TOF neutron powder diffraction technique is presented. Successes and problems in the application of this technique in material science are reported. Powder diffraction technique is very useful when materials, in a single crystal form, reveal complicated electric and magnetic domain structures. Finding and describing the magnetic structure of multiferroics is the great success of ultra-high resolution TOF neutron diffraction. This unique role of the TOF method in discovery of the modulated magnetic structure of BiFeO3 is presented. To date, the TOF powder neutron diffraction technique gives the richest information on the long period modulated magnetic structure of BiFeO3 and its solid solutions. Determination of magnetic moment direction in a crystal lattice is the unique area of application of the TOF technique. The current status and perspectives of the application of the TOF neutron powder diffraction technique in material science are presented in the review. |
BibTeX:
@article{Sosnowska2015,
author = {Sosnowska, I.M.},
title = {The birth of time-of-flight (TOF) neutron powder diffraction at pulsed neutron source (invited)},
journal = {Cryst. Res. Technol.},
year = {2015},
volume = {50},
number = {9-10},
pages = {705--715},
doi = {10.1002/crat.201400439}
}
|
| Sternik M, Couet S, Łazewski J, Jochym P, Parlinski K, Vantomme A, Temst K and Piekarz P (2015), "Dynamical properties of ordered Fe-Pt alloys", J. Alloys Compd.. Vol. 651, pp. 528-536. |
| Abstract: The structure, magnetic properties, and lattice
dynamics of ordered Fe-Pt alloys with three stoichiometric
compositions, Fe |
BibTeX:
@article{Sternik2015,
author = {Sternik, M. and Couet, S. and Łazewski, J. and Jochym, P.T. and Parlinski, K. and Vantomme, A. and Temst, K. and Piekarz, P.},
title = {Dynamical properties of ordered Fe-Pt alloys},
journal = {J. Alloys Compd.},
year = {2015},
volume = {651},
pages = {528--536},
doi = {10.1016/j.jallcom.2015.08.097}
}
|
| Struzik M, Malys M, Krynski M, Wojcik M, Dygas JR, Wrobel W, Krok F and Abrahams I (2015), "Structural and electrical behaviour in Bi14YO22.5", RSC Adv.. Vol. 5(101), pp. 83471-83479. |
| Abstract: Ab initio molecular dynamics calculations show low energy barriers for oxide ion conduction along c -axis channels in β III -Bi 14 YO 22.5 . |
BibTeX:
@article{Struzik2015,
author = {Struzik, M. and Malys, M. and Krynski, M. and Wojcik, M. and Dygas, J. R. and Wrobel, W. and Krok, F. and Abrahams, I.},
title = {Structural and electrical behaviour in Bi14YO22.5},
journal = {RSC Adv.},
year = {2015},
volume = {5},
number = {101},
pages = {83471--83479},
url = {http://xlink.rsc.org/?DOI=C5RA18709E},
doi = {10.1039/C5RA18709E}
}
|
| Świderska K and Jankowska-Kisielińska J (2015), "The Effect of Phase Decomposition on Magnetic Structure of Cu0.4Mn0.3Ni0.3 Alloy", Acta Phys. Pol. A., Feb, 2015. Vol. 127(2), pp. 394-396. |
| Abstract: The purpose of present investigation was to study the effects of phase decomposition of the Cu0.4Mn0.3Ni0.3 alloy on its magnetic ordering. The single-crystal sample was examined by elastic neutron scattering before and after five subsequent annealing runs. The results indicate that in small fraction of the quenched sample volume there are two types of antiferromagnetic order: one of them AF1 of the long range, the other one of the short range. Ageing induces phase decomposition which yields disappearance of AF1 long range order and increase of the volume of new ordered phase. The results of the investigations of the aged sample indicate that regions of new tetragonal phase exhibit antiferromagnetic ordering with magnetic moments of Mn atoms arranged as in the pure compound MnNi but with unequal domain distribution. The intensity of magnetic component of super-structure reflections increases with the duration of ageing at lower rate than component due to atomic order. |
BibTeX:
@article{widerska2015,
author = {Świderska, K. and Jankowska-Kisielińska, J.},
title = {The Effect of Phase Decomposition on Magnetic Structure of Cu 0.4 Mn 0.3 Ni 0.3 Alloy},
journal = {Acta Phys. Pol. A},
year = {2015},
volume = {127},
number = {2},
pages = {394--396},
url = {http://przyrbwn.icm.edu.pl/APP/PDF/127/a127z2p075.pdf},
doi = {10.12693/APhysPolA.127.394}
}
|
| Szewczyk D, Jeżowski A, Vdovichenko G, Krivchikov A, Bermejo F, Tamarit J, Pardo L and Taylor J (2015), "Glassy Dynamics versus Thermodynamics: The Case of 2-Adamantanone", J. Phys. Chem. B. Vol. 119(26), pp. 8468-8474. |
| Abstract: The heat capacity and thermal conductivity of the monoclinic and the fully ordered orthorhombic phases of 2-adamantanone (C10H14O) have been measured for temperatures between 2 and 150 K. The heat capacities for both phases are shown to be strikingly close regardless of the site disorder present in the monoclinic crystal which arises from the occupancy of three nonequivalent sites for the oxygen atom. The heat capacity curves are also well accounted for by an evaluation carried out within the harmonic approximation in terms of the g vibrational frequency distributions measured by means of inelastic neutron scattering. Such spectral functions show however a significant excess of low frequency modes for the crystal showing statistical disorder. In contrast, large differences are found for the thermal conductivity which contrary to what could be expected, shows the substitutionally disordered crystal to exhibit better heat transport properties than the fully ordered orthorhombic phase. Such an anomalous behavior is understood from examination of the crystalline structure of the orthorhombic phase which leads to very strong scattering of heat-carrying phonons due to grain boundary effects able to yield a largely reduced value of the conductivity as well as to a plateau-like feature at intermediate temperatures which contrasts with a bell-shaped maximum shown by data pertaining the disordered crystal. The relevance of the present findings within the context of glassy dynamics of the orientational glass state is finally discussed. |
BibTeX:
@article{Szewczyk2015,
author = {Szewczyk, D. and Jeztextperiodcenteredwski, A. and Vdovichenko, G.A. and Krivchikov, A.I. and Bermejo, F.J. and Tamarit, J.L. and Pardo, L.C. and Taylor, J.W.},
title = {Glassy Dynamics versus Thermodynamics: The Case of 2-Adamantanone},
journal = {J. Phys. Chem. B},
year = {2015},
volume = {119},
number = {26},
pages = {8468--8474},
doi = {10.1021/acs.jpcb.5b04240}
}
|
| Szostak E, Hetmanczyk J and Migdał-Mikuli A (2015), "Inelastic and elastic neutron scattering studies of the vibrational and reorientational dynamics, crystal structure and solid-solid phase transition in [Mn(OS(CH3)2)6](ClO4)2 supported by theoretical (DFT) calculations", Spectrochim. Acta - Part A Mol. Biomol. Spectrosc., Jun, 2015. Vol. 145, pp. 368-375. |
| Abstract: Abstract The vibrational and reorientational dynamics of CH3 groups from (CH3)2SO ligands in the high- and low-temperature phases of [Mn(OS(CH3)2)6](ClO4)2 were investigated by quasielastic and inelastic incoherent neutron scattering (QENS and IINS) methods. The results show that above the phase transition temperature (detected earlier by differential scanning calorimetry (DSC) at TC5c = 222.9 K on cooling and at TC5h = 225.4 K on heating) the CH3 groups perform fast (τR ≈ 10-12-10-13 s) reorientational motions. These motions start to slow down below TC5c Neutron powder diffraction (NPD) measurements, performed simultaneously with QENS and IINS, indicated that this phase transition is associated with a change of the crystal structure, too. Theoretical infrared absorption, Raman and inelastic incoherent neutron scattering spectra were calculated using DFT method (B3LYP functional, LANL2DZ ECP basis set (on Mn atom) and 6-311+G(d,p) basis set (on C, H, S, O atoms) for the isolated equilibrium model (isolated [Mn(DMSO)6]2+ cation and ClO4- anion). Calculated spectra show a good agreement with the experimental spectra (FT-IR, RS and IINS). The comparison of the results obtained by these complementary methods was made. |
BibTeX:
@article{Szostak2015,
author = {Szostak, Elzbieta and Hetmanczyk, Joanna and Migdał-Mikuli, Anna},
title = {Inelastic and elastic neutron scattering studies of the vibrational and reorientational dynamics, crystal structure and solid-solid phase transition in [Mn(OS(CH3)2)6](ClO4)2 supported by theoretical (DFT) calculations},
journal = {Spectrochim. Acta - Part A Mol. Biomol. Spectrosc.},
year = {2015},
volume = {145},
pages = {368--375},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1386142515003339},
doi = {10.1016/j.saa.2015.03.037}
}
|
| Tsvyashchenko AV, Salamatin DA, Sidorov VA, Petrova AE, Fomicheva LN, Kichanov SE, Salamatin AV, Velichkov A, Kozlenko DR, Nikolaev AV, Ryasny GK, Makarova OL, Menzel D and Budzyński M (2015), "Incommensurate antiferromagnetism induced by a charge density wave in the cubic phase of TbGe2.85", Phys. Rev. B - Condens. Matter Mater. Phys., Sep, 2015. Vol. 92(10), pp. 104426. |
| Abstract: Temperature dependencies of the electrical resistivity, magnetic susceptibility, and heat capacity have been obtained in the cubic phase of TbGe2.85 (the AuCu3 structure), synthesized at high pressure. The macroscopic measurements indicate that a charge density wave is formed below 145 K and an antiferromagnetic ordering is realized below 19 K. Hyperfine interaction data obtained with the time differential perturbed angular correlation method with Cd111 probes inserted in the TbGe2.85 lattice suggest that the charge density wave is incommensurate in the temperature region 19-145 K, but becomes commensurate below 19 K. The neutron diffraction reveals a complex antiferromagnetic spiral structure in the magnetically ordered phase. We discuss relations between the charge density wave and helical ordering in TbGe2.85 and TbPd3. |
BibTeX:
@article{Tsvyashchenko2015,
author = {Tsvyashchenko, A. V. and Salamatin, D. A. and Sidorov, V. A. and Petrova, A. E. and Fomicheva, L. N. and Kichanov, S. E. and Salamatin, A. V. and Velichkov, A. and Kozlenko, D. R. and Nikolaev, A. V. and Ryasny, G. K. and Makarova, O. L. and Menzel, D. and Budzynski, M.},
title = {Incommensurate antiferromagnetism induced by a charge density wave in the cubic phase of TbGe2.85},
journal = {Phys. Rev. B - Condens. Matter Mater. Phys.},
year = {2015},
volume = {92},
number = {10},
pages = {104426},
url = {https://link.aps.org/doi/10.1103/PhysRevB.92.104426},
doi = {10.1103/PhysRevB.92.104426}
}
|
| Waliszewski J and Rećko K (2015), "Magnetization distribution in noncollinear magnetic systems with mutually perpendicular crystal axes", J. Optoelectron. Adv. Mater.. Vol. 17(7-8), pp. 958-962. |
| Abstract: The method of reconstruction of magnetization distribution in the crystal with noncollinear ordering of magnetic moments in the cubic, tetragonal and orthorhombic crystal structures was described. As an example the neutron diffraction data for ScFe4Al8 were used. It has been shown that in this case noncollinear magnetic system can be conveniently described as composed of three collinear systems. From the analysis of the magnetic structure factors the components of the magnetic moment of each atom in the system can be estimated what further allows for the synthesis of "partial" structure factors. The "partial" structure factors were used as the input data for the reconstruction of "partial" magnetization distributions using the Maximum Entropy Method (MEM). Finally, the full vectorial map of the magnetization distribution was obtained as a linear combination of the "partial" distributions. |
BibTeX:
@article{Waliszewski2015,
author = {Waliszewski, J. and Rećko, K.},
title = {Magnetization distribution in noncollinear magnetic systems with mutually perpendicular crystal axes},
journal = {J. Optoelectron. Adv. Mater.},
year = {2015},
volume = {17},
number = {7-8},
pages = {958--962}
}
|
| Weiß C, Chiaveri E, Girod S, Vlachoudis V, Aberle O, Barros S, Bergström I, Berthoumieux E, Calviani M, Guerrero C, Wright T and Žugec P (2015), "The new vertical neutron beam line at the CERN n-TOF facility design and outlook on the performance", Nucl. Instruments Methods Phys. Res. Sect. A Accel. Spectrometers, Detect. Assoc. Equip.. Vol. 799, pp. 90-98. |
| Abstract: At the neutron time-of-flight facility n-TOF at CERN a new vertical beam line was constructed in 2014, in order to extend the experimental possibilities at this facility to an even wider range of challenging cross-section measurements of interest in astrophysics, nuclear technology and medical physics. The design of the beam line and the experimental hall was based on FLUKA Monte Carlo simulations, aiming at maximizing the neutron flux, reducing the beam halo and minimizing the background from neutrons interacting with the collimator or back-scattered in the beam dump. The present paper gives an overview on the design of the beam line and the relevant elements and provides an outlook on the expected performance regarding the neutron beam intensity, shape and energy resolution, as well as the neutron and photon backgrounds. |
BibTeX:
@article{Weiß2015,
author = {Weiß, C. and Chiaveri, E. and Girod, S. and Vlachoudis, V. and Aberle, O. and Barros, S. and Bergström, I. and Berthoumieux, E. and Calviani, M. and Guerrero, C. and Wright, T. and Žugec, P.},
title = {The new vertical neutron beam line at the CERN n-TOF facility design and outlook on the performance},
journal = {Nucl. Instruments Methods Phys. Res. Sect. A Accel. Spectrometers, Detect. Assoc. Equip.},
year = {2015},
volume = {799},
pages = {90--98},
doi = {10.1016/j.nima.2015.07.027}
}
|
| Wiertel M, Surowiec Z, Budzyński M, Sarzyński J and Beskrovnyi AI (2015), "Magnetic and structural properties of Sc(Fe1-xSix)2 Laves phases studied by Mössbauer spectroscopy and neutron diffraction", Nukleonika., Mar, 2015. Vol. 60(1), pp. 155-160. |
| Abstract: The aim of the presented paper is to study an influence of replacement of Fe atoms by Si atoms in quasibinary Sc(Fe1-xSix)2 Laves phases on their structural and magnetic properties. Powder X-ray diffraction (XRD) and neutron diffraction (ND) measurements carried out at different temperatures from 4.3 K up to about 700 K revealed that samples were single phase with cubic C15 structure for Si concentration x from 0.05 to 0.20 and hexagonal C14 structure for higher concentration. The results of 57Fe Mössbauer measurements showed that the Sc(Fe1-xSix)2 compounds with x ≤ 0.30 are ferrimagnetic at 4.3 K. At temperature 80 K in the samples with x = 0.20 and 0.30, a magnetic cluster spin-glass state has been observed, as ferrimagnetic long- -range order disappears. Such picture was supported by the results of ND measurements carried out at 8 K, which confirmed the lack of long-range order for x above 0.10 and an occurrence of hyperfine field distributions in the corresponding Mössbauer spectra. At room temperature, samples with x ≥ 0.20 became paramagnetic. A substitution of Si atoms for Fe ones leads to a decreasing of mean values of hyperfine magnetic fields in samples under investigation. From the neutron diffraction pattern analysis of Sc(Fe0.90Si0.10)2Fe magnetic moment was determined as to be equal to 1.5 μB at 8 K. Combining this result with a value of hyperfine magnetic field on 57Fe probes, the hyperfine coupling constant A in Sc(Fe0.90Cu0.10)2 phases is estimated at about 11.6 T/μB at 8 K. |
BibTeX:
@article{Wiertel2015,
author = {Wiertel, Marek and Surowiec, Zbigniew and Budzyński, Mieczyslaw and Sarzyński, Jan and Beskrovnyi, Anatoly I.},
title = {Magnetic and structural properties of Sc(Fe1-xSix)2 Laves phases studied by Mössbauer spectroscopy and neutron diffraction},
journal = {Nukleonika},
year = {2015},
volume = {60},
number = {1},
pages = {155--160},
url = {https://www.sciendo.com/article/10.1515/nuka-2015-0032},
doi = {10.1515/nuka-2015-0032}
}
|
| Wojciechowski K, Gutberlet T, Raghuwanshi V and Terry A (2015), "Reverse hydrotropy by complex formation", Phys. Chem. Chem. Phys.. Vol. 17(2), pp. 1106-1113. |
| Abstract: Self-aggregation of three di-N-alkylated diaza-18-crown-6 ethers (ACEs) was studied in non-polar solvents. The three ACEs differed by the length of the alkyl chain: n-decyl (ACE-10), n-hexadecyl (ACE-16) and n-tetracosane (ACE-24). From the previously reported interfacial tension isotherms, the formation of reverse micelles was expected above ACE concentrations of ∼10-3 M. However, the water content analysis in conjunction with Dynamic Light Scattering (DLS), Fluorescence Correlation Spectroscopy (FCS) and 1H NMR Diffusion Ordered Spectroscopy (DOSY) do not provide any clear proof of the existence of aggregates. Only the Small Angle Neutron Scattering (SANS) of concentrated toluene ACE solutions reveals the existence of small reverse micelles (probably ACE dimers forming small cages hosting 1-2 water molecules). On the other hand, spectrophotometric and fluorescence dye dissolution studies using eosin Y, tropaeolin OO and methyl orange suggest that ACEs can dissolve these dyes without requiring the formation of aggregates. This discrepancy was interpreted assuming the dye-ACE complexation as the driving force for dye solubilisation, providing a possible mechanism of reverse hydrotropy ("lipotropy") in non-polar solvents. This example shows that special care should be taken when dye solubilisation is used to probe self-aggregation of an amphiphile in non-polar solvents. The amphiphile-dye complex formation might be responsible for false positive results and the aggregate formation should always be confirmed with other methods. |
BibTeX:
@article{Wojciechowski2015,
author = {Wojciechowski, K. and Gutberlet, T. and Raghuwanshi, V.S. and Terry, A.},
title = {Reverse hydrotropy by complex formation},
journal = {Phys. Chem. Chem. Phys.},
year = {2015},
volume = {17},
number = {2},
pages = {1106--1113},
doi = {10.1039/c4cp03835e}
}
|
| Woźnica N, Hawelek L, Fischer H, Bobrinetskiy I and Burian A (2015), "The atomic scale structure of graphene powder studied by neutron and X-ray diffraction", J. Appl. Crystallogr.. Vol. 48, pp. 1429-1436. |
| Abstract: The structure of graphene obtained by chemical exfoliation of graphite via the oxidation/reduction procedure has been determined using wide-angle scattering of neutrons and X-rays combined with computer simulations based on classical molecular dynamics (MD). A comparison of results obtained from wide-angle neutron scattering (WANS) with the D4 neutron diffractometer dedicated for liquids and amorphous materials (Institute Laue-Langevin in Grenoble) and from wide-angle X-ray scattering (WAXS) with the laboratory Rigaku-Denki D/MAX RAPID II diffractometer has shown that both techniques provide data of a good quality that can be used to derive precise and valuable structural information about graphene. To obtain detailed structural information, the paracrystal formalism has been used along with MD simulations. The MD simulations were performed at 300 K with second-generation reactive empirical bond order potential for atoms lying in the same layer and the Lennard-Jones potential for interlayer interactions. The proposed models consist of three-layered systems, 36 Å in diameter, in which mono-vacancy, di-vacancy and Stone-Thrower-Wales types of defects are introduced. The reported results show that the WANS and WAXS methods together with the MD simulations contribute to a detailed description of the graphene materials, including the presence of topological defects, which is important as their structure at the atomic scale dramatically affects their electrical and mechanical properties. |
BibTeX:
@article{Woznica2015,
author = {Woznica, N. and Hawelek, L. and Fischer, H.E. and Bobrinetskiy, I. and Burian, A.},
title = {The atomic scale structure of graphene powder studied by neutron and X-ray diffraction},
journal = {J. Appl. Crystallogr.},
year = {2015},
volume = {48},
pages = {1429--1436},
doi = {10.1107/S1600576715014053}
}
|
| Yao J, Isnard O, Morozkin AV, Ivanova TI, Koshkid'Ko YS, Bogdanov AE, Nikitin SA and Suski W (2015), "Magnetic order and crystal structure study of YNi4Si-type NdNi4Si", J. Solid State Chem., Feb, 2015. Vol. 222, pp. 123-128. |
| Abstract: Magnetic measurements and neutron powder diffraction investigation of the magnetic structure of the orthorhombic YNi4Si-type (space group Cmmm) NdNi4Si compound are presented. The magnetocaloric effect of NdNi4Si is calculated in terms of the isothermal magnetic entropy change and it reaches the maximum value of -3.3 J/kg K for a field change of 50 kOe near TC=12 K. Below ∼12 K, NdNi4Si exhibits a commensurate b-axis collinear ferromagnetic ordering with the Cmm′m magnetic space group in a zero magnetic field. At 1.5 K, the neodymium atoms have the magnetic moment of 2.37(5) μB. The orthorhombic crystal structure and its thermal evolution are discussed in comparison with the CaCu5-type compound. |
BibTeX:
@article{Yao2015,
author = {Yao, Jinlei and Isnard, O. and Morozkin, A. V. and Ivanova, T. I. and Koshkid'Ko, Yu S. and Bogdanov, A. E. and Nikitin, S. A. and Suski, W.},
title = {Magnetic order and crystal structure study of YNi4Si-type NdNi4Si},
journal = {J. Solid State Chem.},
year = {2015},
volume = {222},
pages = {123--128},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0022459614004952},
doi = {10.1016/j.jssc.2014.11.016}
}
|
| Yartys VA, Antonov VE, Beskrovnyy AI, Crivello JC, Denys RV, Fedotov VK, Gupta M, Kulakov VI, Kuzovnikov MA, Latroche M, Morozov YG, Sheverev SG and Tarasov BP (2015), "Hydrogen-assisted phase transition in a trihydride MgNi2H3 synthesized at high H2 pressures: Thermodynamics, crystallographic and electronic structures", Acta Mater., Jan, 2015. Vol. 82, pp. 316-327. |
| Abstract: MgNi2 intermetallic was synthesized by powder metallurgy and crystallizes with a Laves-type C36 structure (space group P63/mmc (No. 194); a = 4.826; c = 15.832 A˚). At 300 °C during interaction with hydrogen (deuterium) gas compressed to 2.8-7.4 GPa, a trihydride MgNi2H(D)3.2 was synthesized. The trihydride remained metastable at ambient conditions allowing its structure, stability and magnetic properties to be studied. The formation of MgNi2H3.2 is associated with a complete rebuilding of the initial hexagonal structure into the orthorhombic distorted MoSi2-type sublattice (space group Fmmm (No. 69); a = 4.55; b = 4.69; c = 8.80 A˚). Neutron diffraction of the MgNi2D3.2 demonstrated that D atoms fill sites having octahedral Mg4Ni2 (D1/4b) and planar Ni2 (D2/8f) coordination. Within the framework of the density functional theory, density of states (DOS) calculations showed the formation of a structure around -10 to -6 eV caused by the chemical bonds of hydrogen and its 1s states mainly via interaction with the 3d states of Ni. Analysis of the electronic structure revealed a charge transfer from Mg to Ni, and to the H atoms. The calculated enthalpy of formation of MgNi2H3 is about -30 kJ/mol-H2, which is consistent with the stability of the hydride at normal conditions. The initial sample contained a small amount of a secondary MgNi3 intermetallic, which has been formed during the equilibrium interaction of magnesium and nickel at 800 °C. Thus this compound should be included in the phase diagram of the Mg-Ni system. MgNi3 decomposes under high-temperature/high-pressure hydrogenation conditions and forms nickel monohydride. |
BibTeX:
@article{Yartys2015,
author = {Yartys, V. A. and Antonov, V. E. and Beskrovnyy, A. I. and Crivello, J. C. and Denys, R. V. and Fedotov, V. K. and Gupta, M. and Kulakov, V. I. and Kuzovnikov, M. A. and Latroche, M. and Morozov, Yu G. and Sheverev, S. G. and Tarasov, B. P.},
title = {Hydrogen-assisted phase transition in a trihydride MgNi2H3 synthesized at high H2 pressures: Thermodynamics, crystallographic and electronic structures},
journal = {Acta Mater.},
year = {2015},
volume = {82},
pages = {316--327},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1359645414006892},
doi = {10.1016/j.actamat.2014.09.012}
}
|
| Zhang N, Paściak M, Glazer AM, Hlinka J, Gutmann M, Sparkes HA, Welberry TR, Majchrowski A, Roleder K, Xie Y and Ye Z-G (2015), "A neutron diffuse scattering study of PbZrO3 and Zr-rich PbZr1– x TixO3", J. Appl. Crystallogr., Dec, 2015. Vol. 48(6), pp. 1637-1644. |
| Abstract:
A combined neutron diffuse scattering study and model analysis
of the antiferroelectric crystal PbZrO 3 is described.
Following on from earlier X-ray diffuse scattering studies,
supporting evidence for disordering of oxygen octahedral tilts and
Pb displacements is shown in the high-temperature cubic phase.
Excess diffuse scattering intensity is found at the |
BibTeX:
@article{Zhang2015,
author = {Zhang, Nan and Paściak, Marek and Glazer, A. M. and Hlinka, Jirka and Gutmann, Matthias and Sparkes, Hazel A. and Welberry, T. R. and Majchrowski, Andrzej and Roleder, K. and Xie, Yujuan and Ye, Zuo-Guang},
title = {A neutron diffuse scattering study of PbZrO 3 and Zr-rich PbZr 1– x Ti x O 3},
journal = {J. Appl. Crystallogr.},
year = {2015},
volume = {48},
number = {6},
pages = {1637--1644},
url = {https://scripts.iucr.org/cgi-bin/paper?S1600576715017069},
doi = {10.1107/S1600576715017069}
}
|
| Zywczak A, Rusinek D, Czub J, Sikora M, Stepień J, Gondek, Gajewska M, Takasaki A and Hoser A (2015), "Icosahedral hydrides of the Ti45Zr38Ni17-xCox nano-powders", J. Alloys Compd., Jan, 2015. Vol. 656, pp. 702-706. |
| Abstract: In this communication we report the phase transitions associated with a hydrogen uptake in the quasicrystalline Ti45Zr38Ni17-xCox alloys that were prepared by mechanical alloying. The crystal structure evolution of the alloys was characterized by means of the variety of diffraction techniques (X-ray, neutron, and electron) as well as extended X-ray absorption fine structure spectroscopy (EXAFS). That analysis was supported by the results of the thermodynamic measurements, namely differential scanning calorimetry (DSC) and thermal desorption spectroscopy (TDS). According to the neutron diffraction results, the transformation of the amorphous Ti45Zr38Ni17-xCox phases into the quasicrystalline state starts at the temperature of 475°C. At 525°C the icosahedral phase (the i-phase) is well-developed. At higher temperatures the i-phase transforms into the approximant w-phase and eventually into the cubic phase (the c-phase). The investigated icosahedral nano-powders exhibit a high capacity for gaseous H2 reaching 2.2 wt.% at elevated temperatures. After a hydrogen uptake, a complex phase constitution including the simple hydrides is evidenced. Although the i-phases form again after hydrogen desorption, they are accompanied by the additional Zr3Co phase. |
BibTeX:
@article{Zywczak2015,
author = {Zywczak, A. and Rusinek, D. and Czub, J. and Sikora, M. and Stepień, J. and Gondek and Gajewska, M. and Takasaki, A. and Hoser, A.},
title = {Icosahedral hydrides of the Ti45Zr38Ni17-xCox nano-powders},
journal = {J. Alloys Compd.},
year = {2015},
volume = {656},
pages = {702--706},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838815312391},
doi = {10.1016/j.jallcom.2015.09.278}
}
|
| Żywczak A, Rusinek D, Czub J, Sikora M, Stępień J, Gondek, Takasaki A and Hoser A (2015), "Amorphous hydrides of the Ti45Zr38Ni17-xCox nano-powders", Int. J. Hydrogen Energy. Vol. 40(45), pp. 15534-15539. |
| Abstract: The Ti-Zr-Ni alloys can be synthesized in crystalline, amorphous and quasicrystalline phases. They are produced by mechanical alloying or melt-spinning and they are good candidate materials for hydrogen storage applications. In this communication we modified the Ti45Zr38Ni17 compounds by substituting 3d metals (cobalt) for Ni to obtain amorphous phase. The cobalt atoms are located at the same positions as nickel. We describe a series of phase transitions associated with a hydrogen uptake in the amorphous Ti45Zr38Ni17-xCox alloys that were prepared by mechanical alloying. The investigated alloys exhibited a high capacity for gaseous H2 reaching 2.2 wt.% at elevated temperatures. It has been found, that the amorphous powders were decomposed into simple hydrides being exposed to H2 at temperatures above 200 °C. In order to overcome that problem, a processing route to obtain the amorphous hydrides was established. The heated amorphous hydrides underwent an unusual and fascinating transformation into the glassy quasicrystal phase with no hydrogen loss. A further temperature increase triggered another structural transformation into the cubic phase, which was associated with hydrogen release from the structure. The crystal structure evolution was characterized by the variety of diffraction techniques. Thermodynamic properties were studied by differential scanning calorimetry and thermal desorption spectroscopy. |
BibTeX:
@article{Zywczak2015a,
author = {Zywczak, A. and Rusinek, D. and Czub, J. and Sikora, M. and Stępień, J. and Gondek and Takasaki, A. and Hoser, A.},
title = {Amorphous hydrides of the Ti45Zr38Ni17-xCox nano-powders},
journal = {Int. J. Hydrogen Energy},
year = {2015},
volume = {40},
number = {45},
pages = {15534--15539},
doi = {10.1016/j.ijhydene.2015.09.136}
}
|
| Łuczyńska K, Drużbicki K, Lyczko K and Dobrowolski J (2015), "Experimental (X-ray, 13C CP/MAS NMR, IR, RS, INS, THz) and solid-state DFT study on (1:1) Co-crystal of bromanilic acid and 2,6-dimethylpyrazine", J. Phys. Chem. B. Vol. 119(22), pp. 6852-6872. |
| Abstract: A combined structural, vibrational spectroscopy, and solid-state DFT study of the hydrogen-bonded complex of bromanilic acid with 2,6-dimethylpyrazine is reported. The crystallographic structure was determined by means of low-temperature single-crystal X-ray diffraction, which reveals the molecular units in their native protonation states, forming one-dimensional infinite nets of moderate-strength OtextperiodcenteredtextperiodcenteredtextperiodcenteredH-N hydrogen bonds. The nature of the crystallographic forces, stabilizing the studied structure, has been drawn by employing the noncovalent interactions analysis. It was found that, in addition to the hydrogen bonding, the intermolecular forces are dominated by stacking interactions and C-HtextperiodcenteredtextperiodcenteredtextperiodcenteredO contacts. The thermal and calorimetric analysis was employed to probe stability of the crystal phase. The structural analysis was further supported by a computationally assisted 13C CP/MAS NMR study, providing a complete assignment of the recorded resonances. The vibrational dynamics was explored by combining the optical (IR, Raman, TDs-THz) and inelastic neutron scattering (INS) spectroscopy techniques with the state-of-the-art solid-state density functional theory (DFT) computations. Despite the quasi-harmonic approximation assumed throughout the study, an excellent agreement between the theoretical and experimental data was achieved over the entire spectral range, allowing for a deep and possibly thorough understanding of the vibrational characteristics of the system. Particularly, the significant influence of the long-range dipole coupling on the IR spectrum has been revealed. On the basis of a wealth of information gathered, the recent implementation of a dispersion-corrected linear-response scheme has been extensively examined. |
BibTeX:
@article{uczynska2015,
author = {Łuczyńska, K. and Drużbicki, K. and Lyczko, K. and Dobrowolski, J.C.},
title = {Experimental (X-ray, 13C CP/MAS NMR, IR, RS, INS, THz) and solid-state DFT study on (1:1) Co-crystal of bromanilic acid and 2,6-dimethylpyrazine},
journal = {J. Phys. Chem. B},
year = {2015},
volume = {119},
number = {22},
pages = {6852--6872},
doi = {10.1021/acs.jpcb.5b03279}
}
|
| Baczmański A, Gadalińska E, Braham C, Wroński S, le Joncour L, Panicaud B, François M and Klosek V (2014), "Study of Micromechanical Behaviour of Two Phase Polycrystalline Materials Using Diffraction and Self Consistent Model", Mater. Sci. Forum., May, 2014. Vol. 783-786, pp. 2059-2064. |
| Abstract: Diffraction methods for lattice strain measurement provide useful information concerning the nature of grains behaviour during elastoplastic deformation. The main advantage of the diffraction methods is the possibility of studying mechanical properties of polycrystalline materials separately in each phase and in groups of grains with a specific orientation. In this work we present application of the neutron and X-ray diffraction to study “in situ” deformation of two phase stainless steels during tensile loading. The experimental results are compared with self-consistent model. |
BibTeX:
@article{Baczmanski2014,
author = {Baczmański, Andrzej and Gadalińska, Elżbieta and Braham, Chedly and Wroński, Sebastian and le Joncour, Lea and Panicaud, Benoit and François, Manuel and Klosek, Vincent},
title = {Study of Micromechanical Behaviour of Two Phase Polycrystalline Materials Using Diffraction and Self Consistent Model},
journal = {Mater. Sci. Forum},
year = {2014},
volume = {783-786},
pages = {2059--2064},
url = {https://www.scientific.net/MSF.783-786.2059},
doi = {10.4028/www.scientific.net/MSF.783-786.2059}
}
|
| Baczmański A, Gadalińska E, Wroński S, Joncour L, Panicaud B, François M, Braham C, Klosek V and Paradowska A (2014), "Study of stresses in texture components using neutron diffraction", In Mater. Sci. Forum. Vol. 768-769, pp. 289-295. |
| Abstract: In this work a new method for analysis of neutron diffraction results obtained during "in situ" tensile load is proposed and tested. The methodology is based on the measurements of lattice strains during "in situ" tensile test for several hkl reflections and for different orientations of the sample with respect to the scattering vector. As the result the full stress tensor for preferred texture orientations in function of applied stress can be determined with help of crystallite group method. The experimental data are presented and compared with self-consistent model calculations performed for groups of grains corresponding to the measured hkl reflections. textcopyright (2014) Trans Tech Publications, Switzerland. |
BibTeX:
@book{Baczmanski2014a,
author = {Baczmański, A. and Gadalińska, E. and Wroński, S. and Joncour, L.L. and Panicaud, B. and François, M. and Braham, C. and Klosek, V. and Paradowska, A.},
title = {Study of stresses in texture components using neutron diffraction},
booktitle = {Mater. Sci. Forum},
year = {2014},
volume = {768-769},
pages = {289--295},
doi = {10.4028/www.scientific.net/MSF.768-769.289}
}
|
| Batko I, Batkova M, Tran V, Keiderling U and Filipov V (2014), "Evidence for magnetic phase separation in colossal magnetoresistance compound EuB5.99C0.01", Solid State Commun., Jul, 2014. Vol. 190, pp. 23-27. |
| Abstract: EuB5.99C0.01 is a low-carrier density ferromagnet that is believed to be intrinsically inhomogeneous due to fluctuations of carbon content. In accordance with our previous studies, electric transport of EuB5.99C0.01 close above the temperature of the bulk ferromagnetic (FM) ordering is governed by magnetic polarons. Carbon-rich regions are incompatible with FM phase and therefore they act as spacers preventing magnetic polarons to link, to form FM clusters, and eventually to percolate and establish a (homogoneous) bulk FM state in this compound, what consequently causes additional (magneto) resistance increase. Below the temperature of the bulk FM ordering, carbon-rich regions give rise to helimagnetic domains, which are responsible for an additional scattering term in the electrical resistivity. Unfortunately, there has not been provided any direct evidence for magnetic phase separation in EuB5.99C 0.01 yet. Here reported results of electrical, heat capacity, Hall resistivity and small-angle neutron scattering studies bring evidence for formation of mixed magnetic structure, and provide consistent support for the previously proposed scenario of the magnetoresistance enhancement in EuB 5.99C0.01. textcopyright 2014 Elsevier Ltd. |
BibTeX:
@article{Batko2014,
author = {Batko, I. and Batkova, M. and Tran, V.H. and Keiderling, U. and Filipov, V.B.},
title = {Evidence for magnetic phase separation in colossal magnetoresistance compound EuB5.99C0.01},
journal = {Solid State Commun.},
year = {2014},
volume = {190},
pages = {23--27},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0038109814001574},
doi = {10.1016/j.ssc.2014.04.007}
}
|
| Borowska-Centkowska A, Liu X, Holdynski M, Malys M, Hull S, Krok F, Wrobel W and Abrahams I (2014), "Conductivity in lead substituted bismuth yttrate fluorites", Solid State Ionics. Vol. 254, pp. 59-64. |
| Abstract: The di-substituted bismuth oxide based oxide ion conducting electrolyte system Bi2.5 + xPb0.5YO5.75 + 3x / 2 - δ (x = 0, 1 and 2) has been investigated by X-ray powder diffraction, a.c. impedance spectroscopy, thermal analysis and X-ray photoelectron spectroscopy. δ-Bi2O3 type phases are observed for all compositions studied and showed no obvious changes in structure up to 850 C. XPS results show an increasing trend in binding energy with increasing x-value. Results from thermal analysis and the thermal variation of the lattice parameter indicate a small degree of reduction occurs at high temperature, which is preserved on quenching. This reduction is reversed on heating at intermediate temperatures. The redox reactions appear to be correlated to a degree of curvature in the Arrhenius plot of conductivity. Measurement of transference numbers indicates that these materials are predominantly ionic conductors, with conductivity values at high temperature comparable with mono-substituted analogues. textcopyright 2013 Elsevier B.V. |
BibTeX:
@article{Borowska-Centkowska2014,
author = {Borowska-Centkowska, A. and Liu, X. and Holdynski, M. and Malys, M. and Hull, S. and Krok, F. and Wrobel, W. and Abrahams, I.},
title = {Conductivity in lead substituted bismuth yttrate fluorites},
journal = {Solid State Ionics},
year = {2014},
volume = {254},
pages = {59--64},
doi = {10.1016/j.ssi.2013.11.015}
}
|
| Drużbicki K and Natkaniec I (2014), "Vibrational properties of water retained in graphene oxide", Chem. Phys. Lett., Apr, 2014. Vol. 600, pp. 106-111. |
| Abstract: Vibrational properties of water molecules retained in the interlayer space of graphene oxide were studied by combining inelastic neutron scattering spectroscopy with density functional theory calculations. The credibility of Lerf-Klinowski model in the description of the amplitude weighted vibrational density of states has been successfully examined. The solid-state plane-wave DFT computations have delivered satisfying qualitative interpretation of the INS spectrum, which was found to be mainly driven by the vibrational dynamics of the retained water. textcopyright 2014 Elsevier B.V. All rights reserved. |
BibTeX:
@article{Druzbicki2014,
author = {Drużbicki, Kacper and Natkaniec, Ireneusz},
title = {Vibrational properties of water retained in graphene oxide},
journal = {Chem. Phys. Lett.},
year = {2014},
volume = {600},
pages = {106--111},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0009261414002322},
doi = {10.1016/j.cplett.2014.03.072}
}
|
| Duraj R, Penc B and Szytuła A (2014), "Magnetic properties and magnetic structure of DyCoSi2 compound", Acta Phys. Pol. A., May, 2014. Vol. 125(5), pp. 1176-1178. |
| Abstract: The results of new magnetic dc and neutron diffraction measurements of DyCoSi2 compound are presented. Below TN equal to 10.9 K the Dy moments form collinear G-type structure with the moment parallel to the c-axis. The value of Dy-moment equal to 5.5(2) μB are smaller than free Dy 3+ ion value (10.0 μB). These and the three-step magnetization process indicate the strong influence of the crystal electric field on the stability of the magnetic order. Increase of the values of the lattice parameters at 1.5 K in reference of these at 20 K indicate magnetostriction effect at low temperatures. |
BibTeX:
@article{Duraj2014,
author = {Duraj, R. and Penc, B. and Szytuła, A.},
title = {Magnetic properties and magnetic structure of DyCoSi2 compound},
journal = {Acta Phys. Pol. A},
year = {2014},
volume = {125},
number = {5},
pages = {1176--1178},
url = {http://przyrbwn.icm.edu.pl/APP/PDF/125/a125z5p20.pdf},
doi = {10.12693/APhysPolA.125.1176}
}
|
| Fennell A, Pomjakushin VY, Uldry A, Delley B, Prévost B, Désilets-Benoit A, Bianchi AD, Bewley RI, Hansen BR, Klimczuk T, Cava RJ and Kenzelmann M (2014), "Evidence for SrHo2O4 and SrDy2O4 as model J1 - J2 zigzag chain materials", Phys. Rev. B - Condens. Matter Mater. Phys., Jun, 2014. Vol. 89(22), pp. 224511. |
| Abstract: Neutron diffraction and inelastic spectroscopy is used to characterize the magnetic Hamiltonian of SrHo2O4 and SrDy2O4. Through a detailed computation of the crystal-field levels we find site-dependent anisotropic single-ion magnetism in both materials, and diffraction measurements show the presence of strong one-dimensional spin correlations. Our measurements indicate that competing interactions of the zigzag chain, combined with frustrated interchain interactions, play a crucial role in stabilizing spin-liquid type correlations in this series. textcopyright 2014 American Physical Society. |
BibTeX:
@article{Fennell2014,
author = {Fennell, A. and Pomjakushin, V. Y. and Uldry, A. and Delley, B. and Prévost, B. and Désilets-Benoit, A. and Bianchi, A. D. and Bewley, R. I. and Hansen, B. R. and Klimczuk, T. and Cava, R. J. and Kenzelmann, M.},
title = {Evidence for SrHo2 O4 and SrDy2 O4 as model J1 - J2 zigzag chain materials},
journal = {Phys. Rev. B - Condens. Matter Mater. Phys.},
year = {2014},
volume = {89},
number = {22},
pages = {224511},
url = {https://link.aps.org/doi/10.1103/PhysRevB.89.224511},
doi = {10.1103/PhysRevB.89.224511}
}
|
| Gagor A, Zajdel P and Többens D (2014), "The phase transitions in CsFe(MoO4)2 triangular lattice antiferromagnet, neutron diffraction and high pressure studies", J. Alloys Compd., Sep, 2014. Vol. 607, pp. 104-109. |
| Abstract: We report on the phase transitions in the triangular lattice antiferromagnet CsFe(MoO4)2 at low temperatures and high pressure using powder neutron and X-ray diffraction, specific heat, magnetic susceptibility and in situ high pressure Raman measurements. CsFe(MoO 4)2 undergoes a structural phase transition induced by the rotation of (MoO4)2- tetrahedra at Tc = 220 K. The transformation is associated with a symmetry decrease from P-3m to P-3. Below 4.5 K the antiferromagnetic long range order appears that is related to the nuclear unit cell by the modulation vector q = (1/3 1/3 0.5). The system adopts '120°' spiral spin structure that has been found in several triangular lattice multiferroics. Under pressure CsFe(MoO4) 2 undergoes a reconstructive phase transition to a much larger superstructure which preserves the super-exchange interactions at low temperatures and allows an additional magnetic long-range order at T ∼ 20 K. textcopyright 2014 Elsevier B.V. |
BibTeX:
@article{Gagor2014,
author = {Gagor, Anna and Zajdel, Paweł and Többens, Daniel},
title = {The phase transitions in CsFe(MoO4)2 triangular lattice antiferromagnet, neutron diffraction and high pressure studies},
journal = {J. Alloys Compd.},
year = {2014},
volume = {607},
pages = {104--109},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838814008627},
doi = {10.1016/j.jallcom.2014.04.049}
}
|
| Gondek Ł, Koźlak K, Czub J, Przewoźnik J, Kupczak A, Sikora W, Hoser A, Prokhnenko O and Tsapatsaris N (2014), "Do the RPdIn (R = rare earth) deuterides break the Switendick rule?", Acta Mater.. Vol. 81, pp. 161-172. |
| Abstract: In this paper we focus our attention on the structural and magnetic properties of the RPdIn (R = La, Ce, Pr, Nd, Ho, Er) deuterides. The RTIn compounds having the ZrNiAl-type of crystal structure were suspected of breaking the Switendick 2 Å limit on the nearest H-H distances. As the search for new materials with extraordinarily short H-H distances is of the utmost importance in the context of hydrogen storage (gaseous or electrochemical), we address this intriguing issue very carefully with X-ray and neutron scattering studies, including in situ experiments under D2pressure and high-resolution time-of-flight neutron scattering. Additionally, symmetrical analysis (SA) of the possible hydrogen occupancies and related distortions of the coordination polyhedra are discussed and placed in the context of the experimental data. In particular, we show that occupancy of a certain position by hydrogen leads to the well-defined structural and magnetic behavior of the hydride. According to our results, the scenario of ultra-low H-H distances must be dismissed for the RPdIn deuterides. As well as interesting structural features, we investigate the magnetic properties of the obtained deuterides, hinting at an unusual phenomenon at low temperatures. According to the results of the magnetic susceptibility, neutron diffraction and inelastic neutron scattering experiments, there are grounds to claim that the CePdInD1.1 compound is a candidate for heavy-fermion behavior. |
BibTeX:
@article{Gondek2014,
author = {Gondek, Ł. and Koźlak, K. and Czub, J. and Przewoźnik, J. and Kupczak, A. and Sikora, W. and Hoser, A. and Prokhnenko, O. and Tsapatsaris, N.},
title = {Do the RPdIn (R = rare earth) deuterides break the Switendick rule?},
journal = {Acta Mater.},
year = {2014},
volume = {81},
pages = {161--172},
doi = {10.1016/j.actamat.2014.08.024}
}
|
| Hetmańczyk J, Hetmańczyk Ł, Migdał-Mikuli A, Mikuli E, Florek-Wojciechowska M and Harańczyk H (2014), "Vibrations and reorientations of H2O molecules in [Sr(H2O)6]Cl2 studied by Raman light scattering, incoherent inelastic neutron scattering and proton magnetic resonance", Spectrochim. Acta Part A Mol. Biomol. Spectrosc., Apr, 2014. Vol. 124, pp. 429-440. |
| Abstract: Vibrational-reorientational dynamics of H2O ligands in the high- and low-temperature phases of [Sr(H2O)6]Cl2 was investigated by Raman Spectroscopy (RS), proton magnetic resonance ( 1H NMR), quasielastic and inelastic incoherent Neutron Scattering (QENS and IINS) methods. Neutron powder diffraction (NPD) measurements, performed simultaneously with QENS, did not indicated a change of the crystal structure at the phase transition (detected earlier by differential scanning calorimetry (DSC) at TCh=252.9K (on heating) and at TCc=226.5K (on cooling)). Temperature dependence of the full-width at half-maximum (FWHM) of νs(OH) band at ca. 3248 cm-1 in the RS spectra indicated small discontinuity in the vicinity of phase transition temperature, what suggests that the observed phase transition may be associated with a change of the H2O reorientational dynamics. However, an activation energy value (Ea) for the reorientational motions of H2O ligands in both phases is nearly the same and equals to ca. 8 kJ mol-1. The QENS peaks, registered for low temperature phase do not show any broadening. However, in the high temperature phase a small QENS broadening is clearly visible, what implies that the reorientational dynamics of H2O ligands undergoes a change at the phase transition. 1H NMR line is a superposition of two powder Pake doublets, differentiated by a dipolar broadening, suggesting that there are two types of the water molecules in the crystal lattice of [Sr(H2O)6]Cl2 which are structurally not equivalent average distances between the interacting protons are: 1.39 and 1.18 Å. However, their reorientational dynamics is very similar (τc = 3.3 × 10-10 s). Activation energies for the reorientational motion of these both kinds of H2O ligands have nearly the same values in an experimental error limit: and equal to ca. 40 kJ mole-1. The phase transition is not seen in the 1H NMR spectra temperature dependencies. Infrared (IR), Raman (RS) and inelastic incoherent neutron scattering (IINS) spectra were calculated by the DFT method and quite a good agreement with the experimental data was obtained. textcopyright 2014 Elsevier B.V. All rights reserved. |
BibTeX:
@article{Hetmanczyk2014,
author = {Hetmańczyk, Joanna and Hetmańczyk, Łukasz and Migdał-Mikuli, Anna and Mikuli, Edward and Florek-Wojciechowska, Małgorzata and Harańczyk, Hubert},
title = {Vibrations and reorientations of H2O molecules in [Sr(H2O)6]Cl2 studied by Raman light scattering, incoherent inelastic neutron scattering and proton magnetic resonance},
journal = {Spectrochim. Acta Part A Mol. Biomol. Spectrosc.},
year = {2014},
volume = {124},
pages = {429--440},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1386142514000754},
doi = {10.1016/j.saa.2014.01.054}
}
|
| Holderna-Natkaniec K, Natkaniec I, Fojud Z and Peplinska B (2014), "An inelastic incoherent neutron scattering study of the internal dynamics of ergocalciferol and cholesterol", J. Phys. Conf. Ser., Nov, 2014. Vol. 554(1), pp. 012010. |
| Abstract: A model of the methyl group dynamics of two steroid compounds: cholesterol and ergocalciferol was proposed on the grounds of complementary studies performed by inelastic incoherent neutron scattering, nuclear magnetic resonance and quantum chemistry calculation methods. |
BibTeX:
@article{Holderna-Natkaniec2014,
author = {Holderna-Natkaniec, K. and Natkaniec, I. and Fojud, Z. and Peplinska, B.},
title = {An inelastic incoherent neutron scattering study of the internal dynamics of ergocalciferol and cholesterol},
journal = {J. Phys. Conf. Ser.},
year = {2014},
volume = {554},
number = {1},
pages = {012010},
url = {https://iopscience.iop.org/article/10.1088/1742-6596/554/1/012010},
doi = {10.1088/1742-6596/554/1/012010}
}
|
| Kamiński R, Domagała S, Jarzembska K, Hoser A, Sanjuan-Szklarz W, Gutmann M, Makal A, Malińska M, Ba̧k J and Woźniak K (2014), "Statistical analysis of multipole-model-derived structural parameters and charge-density properties from high-resolution X-ray diffraction experiments", Acta Crystallogr. Sect. A Found. Adv.. Vol. 70(1), pp. 72-91. |
| Abstract: A comprehensive analysis of various properties derived from multiple high-resolution X-ray diffraction experiments is reported. A total of 13 charge-density-quality data sets of α-oxalic acid dihydrate (C2H2O4textperiodcentered2H2O) were subject to Hansen-Coppens-based modelling of electron density. The obtained parameters and properties were then statistically analysed yielding a clear picture of their variability across the different measurements. Additionally, a computational approach (CRYSTAL and PIXEL programs) was utilized to support and examine the experimental findings. The aim of the study was to show the real accuracy and interpretation limits of the charge-density-derived data. An investigation of raw intensities showed that most of the reflections (60-70%) fulfil the normality test and the lowest ratio is observed for weak reflections. It appeared that unit-cell parameters are determined to the order of 10-3° (for cell edges) and 10 -2° (for angles), and compare well with the older studies of the same compound and with the new 100 K neutron diffraction data set. Fit discrepancy factors are determined within a 0.5% range, while the residual density extrema are about ±0.16 (3)°-3. The geometry is very well reproducible between different data sets. Regarding the multipole model, the largest errors are present on the valence shell charge-transfer parameters. In addition, symmetry restrictions of multipolar parameters, with respect to local coordinate systems, are well preserved. Standard deviations for electron density are lowest at bond critical points, being especially small for the hydrogen-bonded contacts. The same is true for kinetic and potential energy densities. This is also the case for the electrostatic potential distribution, which is statistically most significant in the hydrogen-bonded regions. Standard deviations for the integrated atomic charges are equal to about 0.1 e. Dipole moments for the water molecule are comparable with the ones presented in various earlier studies. The electrostatic energies should be treated rather qualitatively. However, they are quite well correlated with the PIXEL results. textcopyright 2014 International Union of Crystallography. |
BibTeX:
@article{Kaminski2014,
author = {Kamiński, R. and Domagała, S. and Jarzembska, K.N. and Hoser, A.A. and Sanjuan-Szklarz, W.F. and Gutmann, M.J. and Makal, A. and Malińska, M. and Ba̧k, J.M. and Woźniak, K.},
title = {Statistical analysis of multipole-model-derived structural parameters and charge-density properties from high-resolution X-ray diffraction experiments},
journal = {Acta Crystallogr. Sect. A Found. Adv.},
year = {2014},
volume = {70},
number = {1},
pages = {72--91},
doi = {10.1107/S2053273313028313}
}
|
| Kolano-Burian A, Włodarczyk P, Hawelek L, Kolano R, Polak M, Zackiewicz P and Temleitner L (2014), "Impact of cobalt content on the crystallization pattern in the Finemet-type ribbons", J. Alloys Compd.. Vol. 615(S1), pp. S203-S207. |
| Abstract: In this paper, crystallization behavior of BCC iron phase in two Finemet-type ribbons with different cobalt content has been studied. Studied ribbons consist of 58.8 and 65 M percents of cobalt (Fe14.7Co58.8Cu1Nb3Si13.5B9 and Fe13.8Co65Cu0.6Nb2.6Si9B9). Identification of crystallized phase has been performed by means of X-ray diffraction and Neutron Diffraction. Kinetics parameters of this process have been obtained through the Differential Scanning Calorimetry measurements with different heating rates. The main aim of this work was to check the correlation between the kinetic parameters such as activation energy, rate constant and crystallization difficulty and the cobalt content in the studied ribbons. It was shown that the slight increase of cobalt amount leads to the significant change of activation energy from 300 to 250 kJ/mol. |
BibTeX:
@article{Kolano-Burian2014,
author = {Kolano-Burian, A. and Wlodarczyk, P. and Hawelek, L. and Kolano, R. and Polak, M. and Zackiewicz, P. and Temleitner, L.},
title = {Impact of cobalt content on the crystallization pattern in the Finemet-type ribbons},
journal = {J. Alloys Compd.},
year = {2014},
volume = {615},
number = {S1},
pages = {S203--S207},
doi = {10.1016/j.jallcom.2013.12.066}
}
|
| Kruk I and Zajdel P (2014), "Single crystal growth and structural characterization of iron telluride doped with chromium and zinc", J. Cryst. Growth. Vol. 401, pp. 608-612. |
| Abstract: An attempt to grow single crystals of Fe1.1-xMxTe (M=Cr, Zn) by crystallization from melt was undertaken. 4 trial growths for each element were performed with nominal compositions x=0.01, 0.025, 0.05 and 0.1. The characterization of obtained crystals was done using scanning electron microscope (SEM) revealed minimal (<1%) concentrations of the dopant, indicating very low solubility limit. Despite minimal concentrations of dopant, a notable change in the quality of the cleavage surfaces was observed, which were much better in the case of zinc doped samples. The structural details of crystals were obtained using single crystal diffraction and revealed that the prominent difference between the samples was caused by the content of the excess iron. The remaining parts of the samples were used for a neutron powder diffraction study, which demonstrated that the dopant influences structural and magnetic properties of the matrix albeit only in the polycrystalline form. Powdered samples with chromium revealed gradual decrease of the ordered magnetic moment and for the highest nominal Cr content only the orthorhombic part of the structural distortion remained at 5 K. On the other hand, sample synthesized with the highest zinc content showed almost no difference from the pure commensurate FeTe. |
BibTeX:
@article{Kruk2014,
author = {Kruk, I.I. and Zajdel, P.},
title = {Single crystal growth and structural characterization of iron telluride doped with chromium and zinc},
journal = {J. Cryst. Growth},
year = {2014},
volume = {401},
pages = {608--612},
doi = {10.1016/j.jcrysgro.2013.11.037}
}
|
| Kulszewicz-Bajer I, Louarn G, Djurado D, Skorka L, Szymanski M, Mevellec J, Rols S and Pron A (2014), "Vibrational dynamics in dendridic oligoarylamines by raman spectroscopy and incoherent inelastic neutron scattering", J. Phys. Chem. B. Vol. 118(19), pp. 5278-5288. |
| Abstract: Vibrational dynamics in triarylamine dendrimers was studied in a complementary way by Raman and infrared (IR) spectroscopies and incoherent inelastic neutron scattering (IINS). Three molecules were investigated, namely, unsubstituted triarylamine dendrimer of the first generation and two dendrimers of the first and second generation, substituted in the crown with butyl groups. To facilitate the assignment of the observed IR and Raman modes as well as the IINS peaks, vibrational models, based on the general valence force field method (GVFF), were calculated for all three compounds studied. A perfect consistency between the calculated and experimental results was found. Moreover, an important complementarity of the vibrational spectroscopies and IINS was established for the investigated dendrimers. The IINS peaks originating mainly from the C-H motions were not restricted by particular selection rules and only dependent on the IINS cross section. To the contrary, Raman and IR bands were imposed by the selection rules and the local geometry of the dendrimers yielding mainly C-C and C-N deformation modes with those of C-H nature of much lower intensity. Raman spectroscopy was also applied to the studies of the oxidation of dendrimers to their cationic forms. A strong Raman resonance effect was observed, since the spectra of the studied compounds, registered at different levels of their oxidation, strongly depended on the position of the excitation line with respect to their electronic spectrum. In particular, the blue (458 nm) excitation line turned out to be insensitive toward the cationic forms yielding very limited spectral information. To the contrary, the use of the red (647 nm) and infrared (1064 nm) excitation lines allowed for an unambiguous monitoring of the spectral changes in dendrimers oxidized to nominally monocationic and tricationic states. The analysis of oxidation-induced spectral changes in the tricationic state indicated that the charge storage configuration predominantly involved one spinless dication of the quinoid bond sequence and one radical cation. However, small numbers of dications were also found in a nominally monocationic state, where only radical cations should have been present. This finding was indicative of some inhomogeneity of the oxidation. textcopyright 2014 American Chemical Society. |
BibTeX:
@article{Kulszewicz-Bajer2014,
author = {Kulszewicz-Bajer, I. and Louarn, G. and Djurado, D. and Skorka, L. and Szymanski, M. and Mevellec, J.Y. and Rols, S. and Pron, A.},
title = {Vibrational dynamics in dendridic oligoarylamines by raman spectroscopy and incoherent inelastic neutron scattering},
journal = {J. Phys. Chem. B},
year = {2014},
volume = {118},
number = {19},
pages = {5278--5288},
doi = {10.1021/jp502735s}
}
|
| Leszczyńska M, Liu X, Wróbel W, Malys M, Dygas JR, Norberg ST, Hull S, Krok F and Abrahams I (2014), "Oxide ion distribution, vacancy ordering and electrical behaviour in the Bi3NbO7 – Bi3YbO6 pseudo-binary system", J. Mater. Chem. A. Vol. 2(43), pp. 18624-18634. |
| Abstract: Total neutron scattering analysis reveals details of cation coordination and vacancy distribution in Bi 3 Nb 1−x Yb x O 7−x . |
BibTeX:
@article{Leszczynska2014,
author = {Leszczynska, M. and Liu, X. and Wrobel, W. and Malys, M. and Dygas, J. R. and Norberg, S. T. and Hull, S. and Krok, F. and Abrahams, I.},
title = {Oxide ion distribution, vacancy ordering and electrical behaviour in the Bi 3 NbO 7 –Bi 3 YbO 6 pseudo-binary system},
journal = {J. Mater. Chem. A},
year = {2014},
volume = {2},
number = {43},
pages = {18624--18634},
url = {http://xlink.rsc.org/?DOI=C4TA03225J},
doi = {10.1039/C4TA03225J}
}
|
| Luczyńska K, Drużbicki K, Łyczko K and Starosta W (2014), "Complementary optical and neutron vibrational spectroscopy study of bromanilic acid: 2,3,5,6-tetramethylpyrazine (1:1) cocrystal", Vib. Spectrosc.. Vol. 75, pp. 26-38. |
| Abstract: Complementary structural and vibrational spectroscopy study of bromanilic acid:2,3,5,6-tetramethylpyrazine (BrA:TMP) 1:1 cocrystal is reported. The crystallographic structure was determined by means of single-crystal X-ray diffraction and can be described as a stacked net of hydrogen-bonded TMPH+BrA-BrA-TMPH+ moieties. The structural analysis was supported by 13CP/MAS NMR study. The complementary vibrational analysis was performed by combining optical (infrared, Raman, terahertz) and inelastic neutron scattering spectroscopy with the state-of-the-art solid-state density functional theory (DFT) computations, which have proven to be superior to the hybrid cluster modeling approach. An excellent agreement between theoretical and experimental data was observed over the entire spectral range, allowing for deep understanding of the vibrational properties. While the primary hydrogen-bonding interactions are limited to the above quoted structural units, the system revealed very little dispersion of the phonon branches, manifested mainly in the intermolecular vibrations range. Moreover, the studied phase does not exhibit any mechanical instability, which could suggest a displacive structural transformation tendency. |
BibTeX:
@article{Luczynska2014,
author = {Luczynska, K. and Druzbicki, K. and Lyczko, K. and Starosta, W.},
title = {Complementary optical and neutron vibrational spectroscopy study of bromanilic acid: 2,3,5,6-tetramethylpyrazine (1:1) cocrystal},
journal = {Vib. Spectrosc.},
year = {2014},
volume = {75},
pages = {26--38},
doi = {10.1016/j.vibspec.2014.09.002}
}
|
| Madsen A and Hoser A (2014), "SHADE3 server: A streamlined approach to estimate H-atom anisotropic displacement parameters using periodic ab initio calculations or experimental information", J. Appl. Crystallogr.. Vol. 47(6), pp. 2100-2104. |
| Abstract: A major update of the SHADE server (http://shade.ki.ku.dk) is presented. In addition to all of the previous options for estimating H-atom anisotropic displacement parameters (ADPs) that were offered by SHADE2, the newest version offers two new methods. The first method combines the original translation-libration-screw analysis with input from periodic ab initio calculations. The second method allows the user to input experimental information from spectroscopic measurements or from neutron diffraction experiments on related structures and utilize this information to evaluate ADPs of H atoms. Tools are provided to set up the ab initio calculations and to derive the internal motion from the calculations. The new server was tested on a range of compounds where neutron diffraction data were available. In most cases, the results are significantly better than previous estimates, and for strong hydrogen bonds in proton sponges, the ab initio calculations become crucial. |
BibTeX:
@article{Madsen2014,
author = {Madsen, A.O. and Hoser, A.A.},
title = {SHADE3 server: A streamlined approach to estimate H-atom anisotropic displacement parameters using periodic ab initio calculations or experimental information},
journal = {J. Appl. Crystallogr.},
year = {2014},
volume = {47},
number = {6},
pages = {2100--2104},
doi = {10.1107/S1600576714022973}
}
|
| Mihalik M, Mat'Aš S, Vavra M, Briančin J, Mihalik M, Fitta M, Kavečanský V and Kopeček J (2014), "Preparation of NdMn1-xFexO3+δ single crystals - Effect of preparation atmosphere and iron doping", J. Cryst. Growth., Sep, 2014. Vol. 401, pp. 605-607. |
| Abstract: We present the study of the effect of crystal growth atmosphere (argon or air) and chemical doping (iron) on the quality and oxygen nonstoichiometry of the single crystals with the general formula NdMn1-xFexO3+δ, which were grown by the optical floating zone method. The analysis of the grown ingots showed that in the Ar atmosphere the losses of the oxygen lead to MnO impurities, but in the air atmosphere some Mn3+ions are replaced by Mn4+ions (thence we have observed positive δ). The X-ray Laue diffraction and polarized light microscopy revealed that the twinning of the grown ingots is the common phenomenon. This twinning can be explained by the fact that a/c∼1. Neutron diffraction experiment revealed that the preferential growing directions of the compound are (101) and (010). |
BibTeX:
@article{Mihalik2014,
author = {Mihalik, Matúš and Mat'Aš, S. and Vavra, M. and Briančin, J. and Mihalik, Marián and Fitta, M. and Kavečanský, V. and Kopeček, J.},
title = {Preparation of NdMn 1 - xFexO 3 +δsingle crystals - Effect of preparation atmosphere and iron doping},
journal = {J. Cryst. Growth},
year = {2014},
volume = {401},
pages = {605--607},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0022024813007999},
doi = {10.1016/j.jcrysgro.2013.11.045}
}
|
| Mindur B, Alimov S, Fiutowski T, Schulz C and Wilpert T (2014), "Performance of a Micro-Strip Gas Chamber for event wise, high rate thermal neutron detection with accurate 2D position determination", J. Instrum., Dec, 2014. Vol. 9(12), pp. P12004-P12004. |
| Abstract: A two-dimensional (2D) position sensitive detector for neutron scattering applications based on low-pressure gas amplification and micro-strip technology was built and tested with an innovative readout electronics and data acquisition system. This detector contains a thin solid neutron converter and was developed for time- and thus wavelength-resolved neutron detection in single-event counting mode, which improves the image contrast in comparison with integrating detectors. The prototype detector of a Micro-Strip Gas Chamber (MSGC) was built with a solid natGd/CsI thermal neutron converter for spatial resolutions of about 100 μm and counting rates up to 107 neutrons/s. For attaining very high spatial resolutions and counting rates via micro-strip readout with centre-of-gravity evaluation of the signal amplitude distributions, a fast, channel-wise, self-triggering ASIC was developed. The front-end chips (MSGCROCs), which are very first signal processing components, are read out into powerful ADC-FPGA boards for on-line data processing and thereafter via Gigabit Ethernet link into the data receiving PC. The workstation PC is controlled by a modular, high performance dedicated software suite. Such a fast and accurate system is crucial for efficient radiography/tomography, diffraction or imaging applications based on high flux thermal neutron beam. In this paper a brief description of the detector concept with its operation principles, readout electronics requirements and design together with the signals processing stages performed in hardware and software are presented. In more detail the neutron test beam conditions and measurement results are reported. The focus of this paper is on the system integration, two dimensional spatial resolution, the time resolution of the readout system and the imaging capabilities of the overall setup. The detection efficiency of the detector prototype is estimated as well. |
BibTeX:
@article{Mindur2014,
author = {Mindur, B. and Alimov, S. and Fiutowski, T. and Schulz, C. and Wilpert, T.},
title = {Performance of a Micro-Strip Gas Chamber for event wise, high rate thermal neutron detection with accurate 2D position determination},
journal = {J. Instrum.},
year = {2014},
volume = {9},
number = {12},
pages = {P12004--P12004},
url = {https://iopscience.iop.org/article/10.1088/1748-0221/9/12/P12004},
doi = {10.1088/1748-0221/9/12/P12004}
}
|
| Natkaniec I, Chudoba D, Hetmańczyk Ł, Kazimirov VY, Krawczyk J, Sashin IL and Zalewski S (2014), "Parameters of the NERA spectrometer for cold and thermal moderators of the IBR-2 pulsed reactor", J. Phys. Conf. Ser., Nov, 2014. Vol. 554(1), pp. 012002. |
| Abstract: The inverted geometry time-of-flight spectrometer NERA designed for simultaneous investigation of elastic and inelastic neutron scattering was constructed on a 100 meter long flight path of the IBR-2 reactor at JINR, Dubna, Russia. Spectrometer parameters were optimized for the thermal neutron spectrum of a water moderator at 330 K. Recently, a new type of cold neutron source operating at 30 K was installed in the sector of six horizontal channels. The cold source in combination with the water moderator allows one to effectively use incident neutrons in wide range of wavelengths. |
BibTeX:
@article{Natkaniec2014,
author = {Natkaniec, I. and Chudoba, D. and Hetmańczyk, Ł. and Kazimirov, V Yu and Krawczyk, J. and Sashin, I L and Zalewski, S.},
title = {Parameters of the NERA spectrometer for cold and thermal moderators of the IBR-2 pulsed reactor},
journal = {J. Phys. Conf. Ser.},
year = {2014},
volume = {554},
number = {1},
pages = {012002},
url = {https://iopscience.iop.org/article/10.1088/1742-6596/554/1/012002},
doi = {10.1088/1742-6596/554/1/012002}
}
|
| Ndao M, Lefort R, Cerclier C, Busselez R, Morineau D, Frick B, Ollivier J, Kityk A and Huber P (2014), "Molecular dynamics of pyrene based discotic liquid crystals confined in nanopores probed by incoherent quasielastic neutron scattering", RSC Adv.. Vol. 4(103), pp. 59358-59369. |
| Abstract: Semiconducting nanowires made of discotic columnar liquid crystals can be obtained by impregnation into solid nanoporous templates, and provide new opportunities to tailor devices for organic electronics with promising charge carriers transport properties. These properties are tightly related to the self-assembly and molecular dynamics of the discotic columns inside the nanowires. We recently studied and rationalized the formation of different nanostructures in the columnar phase of pyrene derivative discotics nanoconfined in anodic alumina and porous silicon templates ([Cerclier et al., J. Phys. Chem. C, 2012, 116, 18990-18998, Kityk et al., Soft Matter, 2014, 10, 4522-4534]). We now present the molecular dynamics of nano-confined pyrene derivative mesogenic phases as studied by incoherent quasielastic neutron scattering over a broad range of correlation times. The combination of backscattering and time-of-flight techniques has allowed to describe the nature of the molecular motions at play on the pico to nanosecond time scale. The dynamics of the columnar phase is dominated by fluctuations of the lateral chains, while the onset of larger amplitude motions like whole-body reorientations and slow center-of-mass translational diffusion occurs at high temperature in the isotropic phase. Interestingly, nano-confinement does not qualitatively alter the nature of the molecular dynamics, but essentially blocks the long range translational motions and induces broader distributions of correlation times of the fastest local relaxations. This journal is |
BibTeX:
@article{Ndao2014,
author = {Ndao, M. and Lefort, R. and Cerclier, C.V. and Busselez, R. and Morineau, D. and Frick, B. and Ollivier, J. and Kityk, A.V. and Huber, P.},
title = {Molecular dynamics of pyrene based discotic liquid crystals confined in nanopores probed by incoherent quasielastic neutron scattering},
journal = {RSC Adv.},
year = {2014},
volume = {4},
number = {103},
pages = {59358--59369},
doi = {10.1039/c4ra13032d}
}
|
| Oksiuta Z, Hosemann P, Vogel S and Baluc N (2014), "Microstructure examination of Fe-14Cr ODS ferritic steels produced through different processing routes", J. Nucl. Mater.. Vol. 451(1-3), pp. 320-327. |
| Abstract: Various thermo-mechanical treatments were applied to refine and homogenise grain size and improve mechanical properties of hot-isostatically pressed (HIP) 14%Cr ODS ferritic steel. The grain size was reduced, improving mechanical properties, tensile strength and Charpy impact, however bimodal-like distribution was also observed. As a result, larger, frequently elongated grains with size above 1 μm and refined, equiaxed grains with a diameter ranging from 250 to 500 nm. Neutron diffraction measurements revealed that for HIP followed by hydrostatic extrusion material the strongest fiber texture was observed oriented parallel to the extrusion direction. In comparison with hot rolling and hot pressing methods, this material exhibited promising mechanical properties: the ultimate tensile strength of 1350 MPa, yield strength of 1280 MPa, total elongation of 21.7% and Charpy impact energy of 5.8 J. Inferior Charpy impact energy of ∼3.0 J was measured for HIP and hot rolled material, emphasising that parameters of this manufacturing process still have to be optimised. As an alternative manufacturing route, due to the uniform microstructure and simplicity of the process, hot pressing might be a promising method for production of smaller parts of ODS ferritic steels. Besides, the ductile-to-brittle transition temperature of all thermo-mechanically treated materials, in comparison with as-HIPped ODS steel, was improved by more than 50%, the transition temperature ranging from 50 to 70 °C (323 and 343 K) remains still unsatisfactory. textcopyright 2014 Elsevier B.V. All rights reserved. |
BibTeX:
@article{Oksiuta2014,
author = {Oksiuta, Z. and Hosemann, P. and Vogel, S.C. and Baluc, N.},
title = {Microstructure examination of Fe-14Cr ODS ferritic steels produced through different processing routes},
journal = {J. Nucl. Mater.},
year = {2014},
volume = {451},
number = {1-3},
pages = {320--327},
doi = {10.1016/j.jnucmat.2014.04.004}
}
|
| Pajzderska A, Druz̀bicki K, Gonzalez M, Jenczyk J, Peplińska B, Jarek M, Mielcarek J and Wa̧sicki J (2014), "Experimental and solid-state computational study of structural and dynamic properties in the equilibrium form of temazepam", J. Phys. Chem. B. Vol. 118(24), pp. 6670-6679. |
| Abstract: Structural properties and rotational dynamics of methyl groups in the most stable form of temazepam were investigated by means of 13C CP MAS NMR, quasielastic neutron scattering (QENS), and 1H NMR spin-lattice relaxation methods. The QENS and 1H NMR studies reveal the inequivalency of methyl groups, delivering their activation parameters. The structural properties of the system were explored in frame of periodic density functional theory (DFT) computations, giving insight into the reorientational barriers and providing understanding of the solid-state NMR results. The theoretical computations are shedding light on the intermolecular interactions along their relation with particular asymmetric structural units. textcopyright 2014 American Chemical Society. |
BibTeX:
@article{Pajzderska2014,
author = {Pajzderska, A. and Druz̀bicki, K. and Gonzalez, M.A. and Jenczyk, J. and Peplińska, B. and Jarek, M. and Mielcarek, J. and Wa̧sicki, J.},
title = {Experimental and solid-state computational study of structural and dynamic properties in the equilibrium form of temazepam},
journal = {J. Phys. Chem. B},
year = {2014},
volume = {118},
number = {24},
pages = {6670--6679},
doi = {10.1021/jp502609b}
}
|
| Pawlak T, Paluch P, Jeziorna A, Bujacz G and Potrzebowski M (2014), "Slow and very fast MAS solid state NMR study of biopolymers", Macromol. Symp.. Vol. 339(1), pp. 60-69. |
| Abstract: In the first part of article, the "NMR Crystallography" approach as tool to fine refinement of solid state structure of biopolymers is presented, employing the α polymorph of L-polylactide (PLLA) as model. Slow Magic Angle Spinning (MAS) technique (with spinning rate of sample in range from 1.2-kHz to 8.0-kHz) was used to assign 13C isotropic chemical shifts and values of 13C δii principal elements of chemical shifts tensors (CST). Theoretical 13C shielding parameters σii were obtained employing GIPAW (Gauge Invariant Projector Augmented Wave) method and compared with experimental 13C δii elements. The computed and experimental 13C CP/MAS spectra for WAND (Wide Angle Neutron Diffraction) geometry of powdered α PLLA were evaluated. It was revealed that the computed model of α PLLA model better fit to experimental NMR spectra. In the second part of article the applications of the new NMR methodology, so called very fast MAS (VF MAS) with sample spinning over 60-kHz are presented. The power of this approach is shown employing the 13C and 15N labeled protein, ubiquitin. We revealed that Cross-Polarization with Variable Contact (CPVC) time sequence under very-fast MAS condition performed in two-dimensional (2D) mode is very efficient method to measure accurately the C-H and N-H distances, and to analyze the dynamics of proteins with overlapped resonances in aliphatic and aromatic regions. textcopyright 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
BibTeX:
@article{Pawlak2014,
author = {Pawlak, T. and Paluch, P. and Jeziorna, A. and Bujacz, G.D. and Potrzebowski, M.J.},
title = {Slow and very fast MAS solid state NMR study of biopolymers},
journal = {Macromol. Symp.},
year = {2014},
volume = {339},
number = {1},
pages = {60--69},
doi = {10.1002/masy.201300139}
}
|
| Pawlukojć A and Hetmańczyk Ł (2014), "INS, DFT and temperature dependent IR investigations of dynamical properties of low temperature phase of choline chloride", Chem. Phys.. Vol. 445, pp. 31-37. |
| Abstract: Within the framework of the research the inelastic neutron scattering and temperature dependent infrared spectroscopy investigations of the low temperature phase of choline chloride were performed. The infra-red spectra in wavenumber region 4000-80 cm-1 and in a temperature range 9-300 K were collected. The density functional theory calculations with the periodic boundary conditions for determination and description of the normal modes in the vibration spectra of choline chloride were applied. Bands assigned to the CH3 torsional vibration were observed at 288 and 249 cm-1. From the analysis of the temperature dependence of the full-width-at-half-maximum the activation energy for CH3 group reorientation is found to be equal to 1.6 ± 0.2 kcal/mol. |
BibTeX:
@article{Pawlukojc2014,
author = {Pawlukojć, A. and Hetmańczyk, Ł.},
title = {INS, DFT and temperature dependent IR investigations of dynamical properties of low temperature phase of choline chloride},
journal = {Chem. Phys.},
year = {2014},
volume = {445},
pages = {31--37},
doi = {10.1016/j.chemphys.2014.10.013}
}
|
| Pawlukojć A, Hołderna-Natkaniec K, Bator G and Natkaniec I (2014), "INS, IR, RAMAN, 1H NMR and DFT investigations on dynamical properties of l-asparagine", Vib. Spectrosc.. Vol. 72, pp. 1-7. |
| Abstract: Results of inelastic neutron scattering (INS), infra-red (IR), Raman and 1H NMR spectroscopy used for investigations on the l-asparagine dynamics are reported. The crystallographic structure and experimental vibrational spectra are compared with those calculated by the DFT methods applied to the solid state. Very good conformity of the experimental and theoretical structures has been found. The NH3+ torsional vibration mode is observed in the INS spectra at 494 cm-1, while the bands assigned to the vibrations of the strong NHâ̄O hydrogen bonds are observed at 2849, 2650, and 2480 cm-1 in the IR spectrum. A 1H NMR investigation has been carried out at 26.75 MHz in the temperature range 150-300 K. For l-asparagine the activation energy needed for the NH3+ group reorientation is equal 5.6 kcal/mol. textcopyright 2014 Elsevier B.V. |
BibTeX:
@article{Pawlukojc2014a,
author = {Pawlukojć, A. and Hołderna-Natkaniec, K. and Bator, G. and Natkaniec, I.},
title = {INS, IR, RAMAN, 1H NMR and DFT investigations on dynamical properties of l-asparagine},
journal = {Vib. Spectrosc.},
year = {2014},
volume = {72},
pages = {1--7},
doi = {10.1016/j.vibspec.2014.02.002}
}
|
| Pawlukojć A, Hołderna-Natkaniec K, Bator G and Natkaniec I (2014), "L-glutamine: Dynamical properties investigation by means of INS, IR, RAMAN, 1H NMR and DFT techniques", Chem. Phys.. Vol. 443, pp. 17-25. |
| Abstract: Vibrational spectra of L-glutamine in the solid state were studied using the inelastic neutron scattering (INS), infrared (IR), Raman and 1H NMR spectroscopy techniques. DFT calculation using CASTEP code with the periodic boundary conditions was used to determine and describe the normal modes in the vibrational spectra of pure L-glutamine. An excellent agreement between the calculated and experimental INS, IR and Raman data has been found. Bands assigned to the stretching vibrations of the NH3+ group in hydrogen bonds are observed at 2400, 2618 and 2619 cm-1, while the NH3+ torsion vibration mode is observed at 441 cm-1. The band at 2041 cm-1 is assigned to combinations of the NH3+ bending symmetry vibration and the CO2- rocking vibration and can be used as an "indicator band" for the identification of the NH3+ groups in amino acid. For the L-glutamine an activation energy needed for the NH3+ group reorientation was obtained as 7.4 kcal/mol. It was found, that the combination three spectroscopic methods (INS, IR and Raman) with calculations for the crystal state proved to be an effective tool to investigate dynamical properties of amino acid crystals. |
BibTeX:
@article{Pawlukojc2014b,
author = {Pawlukojć, A. and Hołderna-Natkaniec, K. and Bator, G. and Natkaniec, I.},
title = {L-glutamine: Dynamical properties investigation by means of INS, IR, RAMAN, 1H NMR and DFT techniques},
journal = {Chem. Phys.},
year = {2014},
volume = {443},
pages = {17--25},
doi = {10.1016/j.chemphys.2014.08.003}
}
|
| Penc B, Baran S, Hoser A, Romaka LP and Szytuła A (2014), "Neutron diffraction studies of NdNi5Sn compound", Acta Phys. Pol. A. Vol. 126(3), pp. 772-773. |
| Abstract: The neutron powder diffraction measurements of the NdNi5Sn compound have been performed. The obtained results indicate that this compound crystallizes in a hexagonal CeNi5Sn-type crystal structure described by the space group P63/mmc. The parameters of the crystal structure at 1.55 and 14.8 K are determined. In contradiction to the magnetic data the long-range magnetic ordering was not detected up to 1.55 K. |
BibTeX:
@article{Penc2014,
author = {Penc, B. and Baran, S. and Hoser, A. and Romaka, L. P. and Szytuła, A.},
title = {Neutron diffraction studies of NdNi5Sn compound},
journal = {Acta Phys. Pol. A},
year = {2014},
volume = {126},
number = {3},
pages = {772--773},
doi = {10.12693/APhysPolA.126.772}
}
|
| Prytuliak A, Godlewska E, Mars K and Berthebaud D (2014), "Synchrotron Study of Ag-Doped Mg2Si: Correlation Between Properties and Structure", J. Electron. Mater., Oct, 2014. Vol. 43(10), pp. 3746-3752. |
| Abstract: The crystal structure of Ag-doped Mg2Si was investigated using synchrotron and neutron powder diffraction analysis, including in situ synchrotron x-ray powder diffraction patterns, recorded during a thermal cycle from room temperature up to 600°C. Rietveld refinement of diffraction patterns indicated that Ag doping results in partial substitution at Si sites. During heating, the Mg2Si lattice parameters exhibited a shift in the temperature dependence at 300°C to 350°C, which was attributed to Ag precipitation out of Mg2Si1−xAgx solid solution. In turn, an increase of the Ag present in the Mg2Si lattice after 350°C could be linked to thermally activated diffusion of Ag from β-AgMg phase. The Ag-dopant migration may explain previously outlined instabilities in the thermopower of Ag-doped Mg2Si, e.g., the drop of the Seebeck coefficient value after heating to 150°C to 200°C and its subsequent increase after 350°C to 450°C. |
BibTeX:
@article{Prytuliak2014,
author = {Prytuliak, Anastasiia and Godlewska, Elzbieta and Mars, Krzysztof and Berthebaud, David},
title = {Synchrotron Study of Ag-Doped Mg2Si: Correlation Between Properties and Structure},
journal = {J. Electron. Mater.},
year = {2014},
volume = {43},
number = {10},
pages = {3746--3752},
url = {http://link.springer.com/10.1007/s11664-014-3119-0},
doi = {10.1007/s11664-014-3119-0}
}
|
| Rachwalska M, Natkaniec I, Zborowski K, Hetmańczyk Ł and Urbanek Z (2014), "Inelastic neutron scattering (INS) study of low frequency vibrations and hydrogen bonding of (E)-benzil monoxime", Zeitschrift fur Phys. Chemie. Vol. 228(1), pp. 63-97. |
| Abstract: (E)-benzil monoxime (or (E)-monoxime of 1,2 diphenyloetandion), which is the subject of this paper, belongs to the family of bioactive organic substances. Many of them have been investigated for many years by inelastic, incoherent neutron scattering spectroscopy (IINS) but the investigation of (E)-benzil monoxime is absent from literature. Therefore (E)-benzil monoxime has been investigated using infrared, and IINS spectroscopy. Dimers of (E)-benzil monoxime were considered using B3LYP functional (connection of Becke and Lee-Yang-Parr functionals) combined with the 6-311++G(d,p) basis set method of quantum chemistry in order to improve the results obtained for a single molecule. In (E)-benzil monoxime, extra bands corresponding primarily to hydrogen bond vibrations (γ bending out of plane of hydrogen bond at 312.3, 372, 470.5, 578.3, 703.5, 748.7, 780.4 cm-1, σ stretching of hydrogen bond bridge at 124.3, 140.9, 176.5, 190.1, 223.6, 259.1, 290.5, 501.8, 623.5 cm-1, δ bending in plane of hydrogen bond at 1102.4, 1371,1452,1535, 1630.6 cm-1, λ bending of hydrogen bond bridge at ca. 40 cm-1, ν stretching band OH at 3397 cm -1) have been identified. Some of them could be discovered only by using IINS method and this is the main result of this work. Additionally we'd like to compare the structure of the compound and the structure of oximes previously investigated by us . Taking into account the structure and IINS results for three oximes investigated by us, we can estimate the difference of hydrogen bond power in those three oximes. Hence the power of hydrogen bond in the (E)-benzil monoxime seems to be the smallest in the group of the three compounds: (E)-benzil monoxime, (E)-2-hydroxyimino-2-cyanoacetic acid ethyl ester (2-oxime), acid K salt of 2-oxime. |
BibTeX:
@article{Rachwalska2014,
author = {Rachwalska, M. and Natkaniec, I. and Zborowski, K. and Hetmańczyk, Ł. and Urbanek, Z.},
title = {Inelastic neutron scattering (INS) study of low frequency vibrations and hydrogen bonding of (E)-benzil monoxime},
journal = {Zeitschrift fur Phys. Chemie},
year = {2014},
volume = {228},
number = {1},
pages = {63--97},
doi = {10.1515/zpch-2014-0441}
}
|
| Rajewska A, Medrzycka K and Hallmann E (2014), "Small-angle neutron scattering study of the structure of mixed micellar solutions based on nonionic and two cationic surfactants", Phys. Solid State. Vol. 56(1), pp. 125-128. |
| Abstract: The aggregation in mixed water systems based on nonionic surfactant, i.e., heptaethylene glycol monotetradecyl ether (C14E7), and cationic surfactants, i.e., cetyltrimethylammonium bromide (CTAB) and cetyltrimethylammonium chloride (CTAC), has been investigated using the small-angle neutron scattering method. The preliminary results of the study of the behavior of C14E7 aqueous solutions (for a concentration of 0.17%) when adding various small amounts of classical cationic surfactants (CTAB and CTAC) have been presented. textcopyright 2014 Pleiades Publishing, Ltd. |
BibTeX:
@article{Rajewska2014,
author = {Rajewska, A. and Medrzycka, K. and Hallmann, E.},
title = {Small-angle neutron scattering study of the structure of mixed micellar solutions based on nonionic and two cationic surfactants},
journal = {Phys. Solid State},
year = {2014},
volume = {56},
number = {1},
pages = {125--128},
doi = {10.1134/S1063783414010302}
}
|
| Rajewska A and Wilk K (2014), "Structure of dilute micellar water solutions of nonionic dimeric surfactant study by small angle neutron scattering method", Acta Phys. Pol. A. Vol. 126(6), pp. 1272-1274. |
| Abstract: The new sugar gemini nonionic surfactant - bis(C12LA) [(C56H110N4O22)] was investigated by small angle neutron scattering method for six dilute solutions with concentrations: 20 CMC, 50 CMC, 75 CMC, 100 CMC, 125 CMC and 150 CMC (CMC= 7.3 × 10-6 mol/dm3, CMC = critical micellar concentration) and three temperatures (20 °C, 40 °C and 60 °C) for the q range 0.003-0.4 Å-1. The aim of experiment was to determine the size and shape of micelles as a function of concentration and temperature in heavy water micellar solutions of nonionic dimeric surfactant bis(C12LA). |
BibTeX:
@article{Rajewska2014a,
author = {Rajewska, A. and Wilk, K.A.},
title = {Structure of dilute micellar water solutions of nonionic dimeric surfactant study by small angle neutron scattering method},
journal = {Acta Phys. Pol. A},
year = {2014},
volume = {126},
number = {6},
pages = {1272--1274},
doi = {10.12693/APhysPolA.126.1272}
}
|
| Rao MN, Lamago D, Ivanov A, D'Astuto M, Postnikov AV, Hussein RH, Basak T, Chaplot SL, Firszt F, Paszkowicz W, Deb SK and Pagès O (2014), "Lattice dynamics of the model percolation-type (Zn,Be)Se alloy: Inelastic neutron scattering, ab initio study, and shell-model calculations", Phys. Rev. B., Apr, 2014. Vol. 89(15), pp. 155201. |
| Abstract: The random Zn1-xBexSe zincblende alloy is known to exhibit a peculiar three-mode [1×(Zn-Se),2×(Be-Se)] vibration pattern near the Brillouin zone (BZ) center, of the so-called percolation type, apparent in its Raman spectra. This is due to an unusually large contrast between the physical properties (length, ionicity) of the constituting bonds. In the present work, the inelastic neutron scattering is applied to study the dispersion of modes away from the BZ center, with special attention to the q - dependence of the BeSe-like transverse optic doublet. The discussion is supported by calculations of lattice dynamics done both ab initio (using the siesta code) and within the shell model. The BeSe-like doublet is found to survive nearly unchanged throughout the BZ up to the zone edge, indicating that its origin is at the ultimate bond scale. The microscopic mechanism of splitting is clarified by ab initio calculations. Namely, the local lattice relaxation needed to accommodate the contrast in physical properties of the Zn-Se and Be-Se bonds splits the stretching and bending modes of connected, i.e., percolativelike, (Be-Se) bonds. textcopyright 2014 American Physical Society. |
BibTeX:
@article{Rao2014,
author = {Rao, Mala N. and Lamago, D. and Ivanov, A. and D'Astuto, M. and Postnikov, A. V. and Hussein, R. Hajj and Basak, Tista and Chaplot, S. L. and Firszt, F. and Paszkowicz, W. and Deb, S. K. and Pagès, O.},
title = {Lattice dynamics of the model percolation-type (Zn,Be)Se alloy: Inelastic neutron scattering, ab initio study, and shell-model calculations},
journal = {Phys. Rev. B},
year = {2014},
volume = {89},
number = {15},
pages = {155201},
url = {https://link.aps.org/doi/10.1103/PhysRevB.89.155201},
doi = {10.1103/PhysRevB.89.155201}
}
|
| Robouch B, Marcelli A, Cordeiro Raposo F, Robouch P, Kisiel A and Di Giambattista L (2014), "The complex stoichiometry of ternary alloys: What lies beyond the canonical Bernoulli distribution?", Solid State Commun.. Vol. 192, pp. 75-78. |
| Abstract: Structural properties of ternary alloys (C 1-xC′x)Im depend on relative configuration probabilities that change with the relative content x. Relative configuration probabilities depend on the intensity of site occupation preferences. Several ternary systems show ideal quasi-canonical Bernoulli distributions of their configuration, while others are characterized by extreme preferences in which one, several or even all configurations are depressed or even lacking. In cases with extreme preferences, only two binary configurations (CIm and C′Im) occur, with no ternary configuration formed. We discuss here in a statistical framework the site occupation preferences of 16 ternary alloys with B3, B4, L12 and C15 crystallographic structures pointing out the observed deviations from the ideal Bernoulli distribution. textcopyright 2014 Elsevier Ltd. |
BibTeX:
@article{Robouch2014,
author = {Robouch, B.V. and Marcelli, A. and Cordeiro Raposo, F. and Robouch, P. and Kisiel, A. and Di Giambattista, L.},
title = {The complex stoichiometry of ternary alloys: What lies beyond the canonical Bernoulli distribution?},
journal = {Solid State Commun.},
year = {2014},
volume = {192},
pages = {75--78},
doi = {10.1016/j.ssc.2014.05.016}
}
|
| Sheka E, Natkaniec I, Rozhkova N and Holderna-Natkaniec K (2014), "Neutron scattering study of reduced graphene oxide of natural origin", JETP Lett.. Vol. 99(11), pp. 650-655. |
| Abstract: This paper presents a direct confirmation of graphene-like configuration and first suggests the chemical composition of basic structural elements of shungite attributing the latter to reduced graphene oxide nanosheets with an average 11:1:3 (C:O:H) atomic content ratio. textcopyright 2014 Pleiades Publishing, Inc. |
BibTeX:
@article{Sheka2014,
author = {Sheka, E.F. and Natkaniec, I. and Rozhkova, N.N. and Holderna-Natkaniec, K.},
title = {Neutron scattering study of reduced graphene oxide of natural origin},
journal = {JETP Lett.},
year = {2014},
volume = {99},
number = {11},
pages = {650--655},
doi = {10.1134/S0021364014110113}
}
|
| Synoradzki K, Toliński T, Chełkowska G, Bajorek A, Zapotoková M, Reiffers M and Hoser A (2014), "X-ray photoemission, calorimetric, and electrical transport properties of CeCu4MnyAl1-y", J. Alloys Compd., Jul, 2014. Vol. 601, pp. 43-49. |
| Abstract: We report the X-ray photoemission spectra (XPS) and the electrical resistivity measurements for the transition Kondo lattice - spin-glass (SG) in the series CeCu4MnyAl1-y. The study includes additionally the low temperature (down to T = 400 mK) heat capacity results. The XPS measurements revealed that the Ce 4f states are well localized. Electrical resistivity studies illustrate a smooth evolution from the ∼ -ln T relation to the metallic behaviour with the increase of the Mn content. Moreover, the specific heat has been analysed considering the electronic, phonon, Schottky (Crystal Electric Field - CEF), Kondo, and SG contributions. The assumption that the CEF splitting of the energy levels is similar for all the compositions allowed us to estimate the SG and Kondo contribution to the heat capacity. Additionally, the neutron diffraction experiment on the parent CeCu4Mn compound has confirmed that it does not show a long-range magnetic order. textcopyright 2014 Elsevier B.V. All rights reserved. |
BibTeX:
@article{Synoradzki2014,
author = {Synoradzki, K. and Toliński, T. and Chełkowska, G. and Bajorek, A. and Zapotoková, M. and Reiffers, M. and Hoser, A.},
title = {X-ray photoemission, calorimetric, and electrical transport properties of CeCu4MnyAl1-y},
journal = {J. Alloys Compd.},
year = {2014},
volume = {601},
pages = {43--49},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838814004873},
doi = {10.1016/j.jallcom.2014.02.117}
}
|
| Szostak M, Piela K, Hołderna-Natkaniec K, Natkaniec I and Bidzińska E (2014), "Optical nonlinearity and electric conductivity origin study on sucrose crystal by using IR, Raman, INS, NMR, and EPR spectroscopies", Carbohydr. Res.. Vol. 395, pp. 29-37. |
| Abstract: The supposed importance of hydrogen bonds toward the origin of second harmonic generation (SHG) and electric conductivity in crystalline sucrose was investigated by IR (4000-10 cm-1), INS (2000-10 cm-1, at 35 K), polarized Raman (3600-50 cm-1) spectra, and 1H NMR second moment line records in the temperature range 450-80 K. The temperature dependence of NIR (7000-5500 cm-1) polarized spectra gave information about -CH2 motions complementary to NMR results concerning -CH 2OH group rearrangements. The EPR spectra were applied to study the generation of radical ions by exposure to NIR radiation. Density functional theory quantum chemical calculations were performed to reproduce the vibrational spectra in order to complete as far as possible the assignments of bands observed by us and in the literature in sucrose crystals, and to throw more light on the possible reasons of sucrose electric conductivity and optical nonlinearity by the knowledge of theoretical values of dipole moments, polarizabilities, first order hyperpolarizabilities of sucrose molecule and clusters as well as ionization energy and electron affinity. The proton transfer in one specific hydrogen bond parallel to the helical axis b is proposed to be the most important in SHG and conductivity origin. textcopyright 2014 Elsevier Ltd. All rights reserved. |
BibTeX:
@article{Szostak2014,
author = {Szostak, M.M. and Piela, K. and Hołderna-Natkaniec, K. and Natkaniec, I. and Bidzińska, E.},
title = {Optical nonlinearity and electric conductivity origin study on sucrose crystal by using IR, Raman, INS, NMR, and EPR spectroscopies},
journal = {Carbohydr. Res.},
year = {2014},
volume = {395},
pages = {29--37},
doi = {10.1016/j.carres.2014.05.015}
}
|
| Szytuła A, Baran S, Kaczorowski D, Sikora W and Hoser A (2014), "Magnetic ordering in Tm5Ni2In4", J. Alloys Compd., Dec, 2014. Vol. 617, pp. 149-153. |
| Abstract: Physical properties of the Tm5Ni2In4 compound have been investigated by means of magnetometric, calorimetric as well as neutron diffraction measurements. The compound crystallizes in the orthorhombic Lu5Ni2In4-type crystal structure (space group Pbam, No. 55). The reported results indicate that the sample exhibits an antiferromagnetic ordering below TN = 4.1 K. The Tm 3+ ions occupy three crystal positions within unit cell: one 2a site and two 4g sites. Analysis of neutron diffraction data collected at T = 1.5 K, together with group theory symmetry analysis predictions show that Tm magnetic moments form a non-collinear magnetic structure described by the propagation vector k = [0, 1/2, 1/2]. The magnetic moments lie in the (001) plane. textcopyright 2014 Elsevier B.V. All rights reserved. |
BibTeX:
@article{Szytua2014,
author = {Szytuła, A. and Baran, S. and Kaczorowski, D. and Sikora, W. and Hoser, A.},
title = {Magnetic ordering in Tm5Ni2In4},
journal = {J. Alloys Compd.},
year = {2014},
volume = {617},
pages = {149--153},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0925838814018234},
doi = {10.1016/j.jallcom.2014.07.190}
}
|
| Szytuła A, Penc B, Dyakonov V, Baran S and Hoser A (2014), "Neutron diffraction studies of nanoparticle dymnO3 compound", Acta Phys. Pol. A., Jan, 2014. Vol. 125(1), pp. 65-66. |
| Abstract: The neutron powder diffraction (NPD) measurements of the nano-size DyMnO3 manganite have been performed. The obtained results indicate that this compound crystallizes in the orthorhombic crystal structure described by the space group Pnma. The Mn and Dy moments order antiferromagnetically at different temperatures and form modulated magnetic structure described by the propagation vector κ = (κx; 0; 0) with the different values of κx component for the Mn and Dy sublattices. The values of κx component for Mn sublattice increase with decreasing of the temperature and are smaller that in bulk compound. The wide Bragg peaks related to the Dy sublattice suggest that the magnetic order in this sublattice has the cluster-like character. |
BibTeX:
@article{Szytua2014a,
author = {Szytuła, A. and Penc, B. and Dyakonov, V. and Baran, S. and Hoser, A.},
title = {Neutron diffraction studies of nanoparticle dymnO3 compound},
journal = {Acta Phys. Pol. A},
year = {2014},
volume = {125},
number = {1},
pages = {65--66},
url = {http://przyrbwn.icm.edu.pl/APP/PDF/125/a125z1p12.pdf},
doi = {10.12693/APhysPolA.125.65}
}
|
| Tresset G, Tatou M, Le Cœur C, Zeghal M, Bailleux V, Lecchi A, Brach K, Klekotko M and Porcar L (2014), "Weighing Polyelectrolytes Packaged in Viruslike Particles", Phys. Rev. Lett., Sep, 2014. Vol. 113(12), pp. 128305. |
| Abstract: This Letter reports on the remarkable selectivity of capsid proteins for packaging synthetic polyelectrolytes in viruslike particles. By applying the contrast variation method in small-angle neutron scattering, we accurately estimated the mean mass of packaged polyelectrolytes Mp and that of the surrounding capsid Mcap. Remarkably, the mass ratio Mp/Mcap was invariant for polyelectrolyte molecular weights spanning more than 2 orders of magnitude. To do so, capsids either packaged several chains simultaneously or selectively retained the shortest chains that could fit the capsid interior. Our data are in qualitative agreement with theoretical predictions based on free energy minimization and emphasize the importance of protein self-energy. These findings may give new insights into the nonspecific origin of genome selectivity for a number of viral systems. |
BibTeX:
@article{Tresset2014,
author = {Tresset, Guillaume and Tatou, Mouna and Le Cœur, Clémence and Zeghal, Mehdi and Bailleux, Virginie and Lecchi, Amélie and Brach, Katarzyna and Klekotko, Magdalena and Porcar, Lionel},
title = {Weighing Polyelectrolytes Packaged in Viruslike Particles},
journal = {Phys. Rev. Lett.},
year = {2014},
volume = {113},
number = {12},
pages = {128305},
url = {https://link.aps.org/doi/10.1103/PhysRevLett.113.128305},
doi = {10.1103/PhysRevLett.113.128305}
}
|
| Vij J and Kocot A (2014), "Characterisation: Orientational Order Parameters of Nematic Liquid Crystals Determined by Infrared and Raman Spectroscopy", In Biaxial Nematic Liq. Cryst. Theory, Simul. Exp.. , pp. 251-265. |
| Abstract: The study of optical textures of thin liquid crystal films under varying boundary conditions by polarising microscopy is one of the fundamental tools of liquid crystal research and characterisation of mesogenic materials. This chapter explains an investigation of liquid crystal materials in terms of the refractive index. There are many types of liquid crystal phases, but the chapter focuses on the uniaxial and biaxial nematic phases. Next, it explains orientational order parameters of nematic liquid crystals determined by infrared (IR) and Raman Spectroscopy. The chapter also explains the basic issues and main observation methods associated with detecting biaxiality using nuclear magnetic resonance (NMR) spectroscopy. Before proceeding with the analysis of the scattering patterns of various kinds of experimental systems, the chapter describes the different experimental setups and sample preparation techniques used in structural studies of biaxial nematics involving neutron scattering. |
BibTeX:
@book{Vij2014,
author = {Vij, J.K. and Kocot, A.},
title = {Characterisation: Orientational Order Parameters of Nematic Liquid Crystals Determined by Infrared and Raman Spectroscopy},
booktitle = {Biaxial Nematic Liq. Cryst. Theory, Simul. Exp.},
year = {2014},
pages = {251--265},
doi = {10.1002/9781118696316.ch10}
}
|
| Wdowik UD, Parlinski K, Rols S and Chatterji T (2014), "Soft-phonon mediated structural phase transition in GeTe", Phys. Rev. B., Jun, 2014. Vol. 89(22), pp. 224306. |
| Abstract: Inelastic neutron scattering experiments on powder samples of GeTe together with density functional theory investigations of the phonon dynamics in the low- and high-temperature phases of GeTe crystal are reported. The dispersion of phonons in the high-temperature rocksalt phase show soft branches with the lowest one at the Γ high-symmetry point. The structural phase transition in GeTe is reconsidered and shown to be driven by the con-densation of exactly three components of the triply degenerate optical transverse soft-phonon mode at the Brillouin zone center. The mechanism proposed allows us to explain the formation of structural distortions in the low-temperature ferroelectric phase of GeTe revealed by various experiments. A displacive nature of the phase change in crystalline GeTe is supported by the results of the present theoretical studies. textcopyright 2014 American Physical Society. |
BibTeX:
@article{Wdowik2014,
author = {Wdowik, Urszula D. and Parlinski, Krzysztof and Rols, Stéphane and Chatterji, Tapan},
title = {Soft-phonon mediated structural phase transition in GeTe},
journal = {Phys. Rev. B},
year = {2014},
volume = {89},
number = {22},
pages = {224306},
url = {https://link.aps.org/doi/10.1103/PhysRevB.89.224306},
doi = {10.1103/PhysRevB.89.224306}
}
|
| Węglewski W, Basista M, Manescu A, Chmielewski M, Pietrzak K and Schubert T (2014), "Effect of grain size on thermal residual stresses and damage in sintered chromium-alumina composites: Measurement and modeling", Compos. Part B Eng.. Vol. 67, pp. 119-124. |
| Abstract: In this paper we present the results of experimental measurements and numerical modeling of the effect of particle size on the residual thermal stresses arising in sintered metal-matrix composites after cooling down from the fabrication temperature. On example of novel Cr(Re)/Al2O3 composites processed by (i) spark plasma sintering and (ii) hot pressing the residual thermal stresses are measured by neutron diffraction technique and determined by a FEM model based on micro-CT scans of the material microstructure. Then numerical model of microcracking induced by residual stresses is applied to predict the effective Young modulus of the damaged composite. Comparison of the numerical results with the measured data of the residual stresses and Young's modulus is presented and fairly good agreement is noted. textcopyright 2014 Elsevier Ltd. All rights reserved. |
BibTeX:
@article{Weglewski2014,
author = {Węglewski, W. and Basista, M. and Manescu, A. and Chmielewski, M. and Pietrzak, K. and Schubert, Th.},
title = {Effect of grain size on thermal residual stresses and damage in sintered chromium-alumina composites: Measurement and modeling},
journal = {Compos. Part B Eng.},
year = {2014},
volume = {67},
pages = {119--124},
doi = {10.1016/j.compositesb.2014.06.027}
}
|
| Woińska M, Jayatilaka D, Spackman M, Edwards A, Dominiak P, Woźniak K, Nishibori E, Sugimoto K and Grabowsky S (2014), "Hirshfeld atom refinement for modelling strong hydrogen bonds", Acta Crystallogr. Sect. A Found. Adv.. Vol. 70(5), pp. 483-498. |
| Abstract: High-resolution low-temperature synchrotron X-ray diffraction data of the salt l-phenylalaninium hydrogen maleate are used to test the new automated iterative Hirshfeld atom refinement (HAR) procedure for the modelling of strong hydrogen bonds. The HAR models used present the first examples of Z′ > 1 treatments in the framework of wavefunction-based refinement methods. l-Phenylalaninium hydrogen maleate exhibits several hydrogen bonds in its crystal structure, of which the shortest and the most challenging to model is the O - H⋯O intramolecular hydrogen bond present in the hydrogen maleate anion (O⋯O distance is about 2.41Å). In particular, the reconstruction of the electron density in the hydrogen maleate moiety and the determination of hydrogen-atom properties [positions, bond distances and anisotropic displacement parameters (ADPs)] are the focus of the study. For comparison to the HAR results, different spherical (independent atom model, IAM) and aspherical (free multipole model, MM; transferable aspherical atom model, TAAM) X-ray refinement techniques as well as results from a low-temperature neutron-diffraction experiment are employed. Hydrogen-atom ADPs are furthermore compared to those derived from a TLS/rigid-body (SHADE) treatment of the X-ray structures. The reference neutron-diffraction experiment reveals a truly symmetric hydrogen bond in the hydrogen maleate anion. Only with HAR is it possible to freely refine hydrogen-atom positions and ADPs from the X-ray data, which leads to the best electron-density model and the closest agreement with the structural parameters derived from the neutron-diffraction experiment, e.g. the symmetric hydrogen position can be reproduced. The multipole-based refinement techniques (MM and TAAM) yield slightly asymmetric positions, whereas the IAM yields a significantly asymmetric position. textcopyright 2014 International Union of Crystallography. |
BibTeX:
@article{Woinska2014,
author = {Woińska, M. and Jayatilaka, D. and Spackman, M.A. and Edwards, A.J. and Dominiak, P.M. and Woźniak, K. and Nishibori, E. and Sugimoto, K. and Grabowsky, S.},
title = {Hirshfeld atom refinement for modelling strong hydrogen bonds},
journal = {Acta Crystallogr. Sect. A Found. Adv.},
year = {2014},
volume = {70},
number = {5},
pages = {483--498},
doi = {10.1107/S2053273314012443}
}
|
| Wroński S, Baczmański A, Gaj A, Wierzbanowski K, Fitzpatrick ME, Klosek V, Lodini A and Marciszko M (2014), "Neutron diffraction study of elastoplastic behaviour of Al/SiCp metal matrix composite during tensile loading and unloading", In Mater. Sci. Forum. Vol. 772, pp. 117-121. |
| Abstract: The aim of the present work is to study effects occurring during elastoplastic deformation and unloading of Al/SiCp metal-matrix composite material. We have measured lattice strains for both phases independently using two separated diffraction peaks (the 111 reflections of Al and SiC) during in situ tensile testing. Lattice strains were measured in the direction parallel to the applied load. The results were compared with an elastoplastic model in order to find parameters determining the plastic deformation of the Al matrix (critical resolved shear stress and hardening parameter). We have found that during initial deformation relaxation of the thermal stresses occurs in both phases. Afterwards, the distribution of strains measured during the in situ test and unloading of the sample agree very well with self-consistent model predictions. textcopyright (2014) Trans Tech Publications, Switzerland. |
BibTeX:
@inproceedings{Wronski2014,
author = {Wroński, Sebastian and Baczmański, Andrzej and Gaj, Anita and Wierzbanowski, Krzysztof and Fitzpatrick, Michael E. and Klosek, Vincent and Lodini, Alain and Marciszko, Marianna},
title = {Neutron diffraction study of elastoplastic behaviour of Al/SiCp metal matrix composite during tensile loading and unloading},
booktitle = {Mater. Sci. Forum},
year = {2014},
volume = {772},
pages = {117--121},
doi = {10.4028/www.scientific.net/MSF.772.117}
}
|
| Wysokiński MM, Abram M and Spałek J (2014), "Ferromagnetism in UGe2: A microscopic model", Phys. Rev. B - Condens. Matter Mater. Phys., Aug, 2014. Vol. 90(8), pp. 081114. |
| Abstract: The Anderson lattice model is used to explain the principal features of the heavy fermion compound UGe2 by means of the generalized Gutzwiller approach (the statistically consistent Gutzwiller approximation method). This microscopic approach successfully reproduces the magnetic and electronic properties of this material, in qualitative agreement with experimental findings from magnetization measurements, neutron scattering, and de Haas-van Alphen oscillations. Most importantly, it explains the appearance, sequence, character, and evolution in an applied magnetic field of the observed in UGe2 ferromagnetic and paramagnetic phases as an effect of a competition between the f-f electron Coulomb interaction energy and f-conduction electron hybridization. textcopyright 2014 American Physical Society. |
BibTeX:
@article{Wysokinski2014,
author = {Wysokiński, Marcin M. and Abram, Marcin and Spałek, Józef},
title = {Ferromagnetism in UGe2: A microscopic model},
journal = {Phys. Rev. B - Condens. Matter Mater. Phys.},
year = {2014},
volume = {90},
number = {8},
pages = {081114},
url = {https://link.aps.org/doi/10.1103/PhysRevB.90.081114},
doi = {10.1103/PhysRevB.90.081114}
}
|