Article
Materials Science, Multidisciplinary
Wei Zhong, Qiaofu Zhang, Ji-Cheng Zhao
Summary: The study tested 18 diverse binary systems and identified a surprisingly simple model with only one fitting parameter, which can reliably describe the diffusion behavior of binary solid solutions.
Article
Chemistry, Multidisciplinary
Nisha Geng, Katerina P. Hilleke, Li Zhu, Xiaoyu Wang, Timothy A. Strobel, Eva Zurek
Summary: Density functional theory (DFT) calculations were performed on compounds with up to two different metal atoms, and it was found that the size of the metal cation is crucial for the stability of the B-C framework. High-throughput DFT calculations identified 22 dynamically stable XYB6C6 binary-guest compounds, expanding the number of synthesizable phases. The average oxidation state of the metal atoms can tune the density of states and superconducting critical temperature, with KPbB6C6 predicted to have the highest Tc among the studied phases.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
Ajay Annamareddy, Paul M. Voyles, John Perepezko, Dane Morgan
Summary: The bulk and surface dynamics of Cu50Zr50 metallic glass were studied using classical molecular dynamics simulations. The research found differences in dynamics between the surface and bulk during cooling, but their behaviors were very similar at their respective glass transition temperatures. The study also revealed a cage and jump mechanism dominating individual atom motion in the glassy state, with differences in activation energies for bulk and surface diffusion mainly attributed to cage-breaking barriers.
Article
Crystallography
Qingyou Han, Yanfei Liu, Cheng Peng, Zhiwei Liu
Summary: The phenomenon of "pushing-to-engulfment transition (PET)" exists in alloys, where particles are engulfed by the growing crystal during solidification. The experimental results are consistent with the literature data.
Review
Engineering, Aerospace
Elke Sondermann, Thomas Voigtmann, Andreas Meyer
Summary: The influence of gravity on atomic mobility can be assessed using the gravitational Peclet number and gravitational length. The diffusion processes in liquids are dominated by thermal energy of atoms rather than Earth's gravitational force. Experimental data under different gravity conditions confirm that interdiffusion is only influenced by accelerations orders of magnitude larger than Earth's gravity.
MICROGRAVITY SCIENCE AND TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Sixue Zheng, Xiang Wang, Susheng Tan, Guofeng Wang, Scott X. Mao
Summary: In situ atomic-scale compression tests reveal that surface atom diffusion mediates consecutive thinning events and ultimate compression fracture in silver nanocrystals. This work provides new insights into the atomic-scale diffusion-mediated compressive deformation of metallic nanocrystals.
MATERIALS RESEARCH LETTERS
(2022)
Article
Nanoscience & Nanotechnology
Kewei Dong, Jian Kong, X. D. Ruan, Y. Yang, Y. Peng, Q. Zhou, K. H. Wang
Summary: In this study, a specially designed BMG was used as filler metal to successfully join TiAl and Ni-based superalloy, achieving good physical prebonding and metallurgical bonding through superplastic filling and solid-state atomic diffusion. Experimental results showed that no crystallization occurred at the joint after superplastic deformation, indicating compact contacting between base metals and filler metal. Temperature played a crucial role in microstructure evolution of the joint, with increasing diffusion temperature leading to thicker reaction layer and formation of small isotropic phases with high shear strength.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
L. -B He, S. Yang, L. Shangguan, J. -H. Zhu, L. Shi, L. Zhang, L. -P. Tang, J. Sun, H. -T. Zhang, L. -T. Sun
Summary: Metal nanocrystals exhibit antithetical mechanical behaviors, with smaller crystals either showing increased strength or decreased strength. The mechanisms governing these behaviors, including dislocation-starvation induced strengthening and surface diffusion induced softening, are not fully understood. To investigate this, sub-20-nm Au and Co nanocrystals were studied using electrical loading-coupled transmission electron microscopy to create variable temperature conditions. It was found that surface diffusion is more temperature-sensitive than dislocation activities and deformation mechanisms transition when surface diffusion is activated or inhibited. At elevated temperatures, the nanocrystals exhibit liquid-like behaviors with consecutive surface reshaping or collapse-and-reconstruction shape transformations taking place. (c) 2023 Elsevier Ltd. All rights reserved.
MATERIALS TODAY NANO
(2023)
Article
Chemistry, Physical
A. Samiri, A. Khmich, A. Hassani, A. Hasnaoui
Summary: Molecular dynamics simulations were used to investigate the annealing effect on binary Mg25Al75 metallic glasses with different cooling rates, showing changes in local atomic structures with decreasing cooling rates. Annealing led to variations in elastic constants and moduli, indicating improved elastic behavior and resistance to compression.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Zhiyuan Huang, Jianan Fu, Xin Li, Wenxin Wen, Hongji Lin, Yan Lou, Feng Luo, Zhenxuan Zhang, Xiong Liang, Jiang Ma
Summary: This study presents a method of ultrasonic-assisted rapid cold welding of metallic glasses without using any additives, achieving stable bonding of MG interface under high-frequency ultrasonic vibration, low temperature and low stress conditions. The ultrasonic technology accelerates atomic diffusion process, enabling rapid bonding of different compositions of MGs and potential for tuning new materials with new performance.
SCIENCE CHINA-MATERIALS
(2022)
Article
Chemistry, Physical
W. Li, L. Yang, Y. G. Zhang, L. T. Kong, J. F. Li
Summary: This study investigates the crystallization behavior of (Al90Y10)(100-x)Si-x (x = 0, 1, 2, 2.5 and 3 at%) amorphous alloys. The addition of Si affects the crystallization process by advancing the primary crystallization of alpha-Al to lower temperatures, depressing the precipitation of Al4Y, and promoting the crystallization of Al3Y. Si also stabilizes the alpha-Al3Y phase significantly.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Thermodynamics
Yan Xiang, Yucheng Deng, Di Fang, Disen Liang, Weimin Ma
Summary: A series of experiments was conducted to investigate the characteristics of metallic melt-water interactions. The results showed that water pool depth significantly influenced steam explosion and debris bed formation characteristics, and jet breakup length was sensitive to jet diameter and free fall height. Additionally, the features of metallic debris beds were compared with those of oxidic ones in terms of configuration, porosity, and particle morphology and size distribution.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Materials Science, Ceramics
Wenfei Lu, Jo-Chi Tseng, Aihan Feng, Jun Shen
Summary: The study aimed to clarify the structural origin of the enhancement in glass-forming ability of binary NiNb metallic glasses. Ni62.5Nb37.5 alloy exhibited the best glass-forming ability and the densest atomic-packing structure among the four components, with a larger fraction of full icosahedral clusters. The glass structure in Ni62.5Nb37.5 MG was a heterogeneous mixture of interpenetrating icosahedral clusters, forming a chain-like network structure in the matrix. These Ni-centered icosahedra polyhedra played an essential role in controlling GFA.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2021)
Article
Materials Science, Multidisciplinary
Chaitanya Mahajan, Vahid Hasannaeimi, Mayur Pole, Elizabeth Kautz, Bharat Gwalani, Sundeep Mukherjee
Summary: The effect of chemistry change on corrosion mechanisms and passive film characteristics of model Ni-P and Co-P metallic glass coatings on mild steel was investigated. Increasing phosphorus content enhanced corrosion resistance, with the presence of hypophosphite and phosphate anions observed on the corroded surfaces. Enrichment of phosphorus in the passive layer facilitated the restoration of the protective hypophosphite anion layer during dissolution. A correlation between electronic structure and corrosion resistance was established, as the relative work function increased with higher phosphorus content.
Article
Chemistry, Physical
Patrick K. Schelling
Summary: The Soret effect describes the concentration gradients in fluid mixtures under a temperature gradient. By using molecular-dynamics simulation, it has been shown that spatially sinusoidal heat pulses can generate temperature and pressure gradients. Compressional waves are the dominant effect over short timescales, dissipating as the system approaches mechanical equilibrium. Concentration gradients quickly develop during the propagation of compressional waves. Over longer timescales, heat conduction returns the system to thermal equilibrium, restoring a more uniform particle density.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Mikhail A. Kuzovnikov, Vladimir E. Antonov, Thomas Hansen, Alexandre S. Ivanov, Alexander Kolesnikov, Valery Kulakov, Vitaly D. Muzalevsky, Stanislav Savvin, Marek Tkacz
Summary: Three hydrides - PdHx, MoHx, and TiHx - exhibit an inverse isotope effect in superconductivity, where the phase with a heavier hydrogen isotope, deuterium, has a higher critical temperature. The origin of this effect is not yet certain, but the commonly accepted explanation points to the strong anharmonicity of optical hydrogen vibrations.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Multidisciplinary
Raphael Finger, Thomas C. Hansen, Holger Kohlmann
Summary: In situ neutron diffraction is an important technique for characterizing functional materials. A new sapphire single-crystal gas-pressure cell has been developed and evaluated, allowing for studying materials under different temperature and hydrogen pressure conditions. The cell has higher maximum temperatures and lower background noise compared to earlier versions.
JOURNAL OF APPLIED CRYSTALLOGRAPHY
(2022)
Article
Chemistry, Physical
Gohil S. Thakur, Thomas C. Hansen, Walter Schnelle, Shuping Guo, Oleg Janson, Jeroen van den Brink, Claudia Felser, Martin Jansen
Summary: The synthesis, crystal structure, and magnetic properties of a new 2:1 ordered triple perovskite Sr3CaOs2O9 were reported. It exhibits a unique buckled honeycomb lattice of osmium, high Neel temperature of approximately 385 K, and electrical insulating behavior.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Inorganic & Nuclear
Simon R. Larsen, Vitalii Shtender, Daniel Hedlund, Erna K. Delczeg-Czirjak, Premysl Beran, Johan Cedervall, Alena Vishina, Thomas C. Hansen, Heike C. Herper, Peter Svedlindh, Olle Eriksson, Martin Sahlberg
Summary: The atomic and magnetic structures of Mn(Co,Ge)2, which crystallizes in a superstructure of the MgZn2-type structure, have been reported. The system exhibits different magnetic structures at different temperatures.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Rasmus Palm, Kenneth Tuul, Frank Elson, Elisabetta Nocerino, Ola K. Forslund, Thomas C. Hansen, Jaan Aruvali, Martin Mansson
Summary: This study investigates the influence of adding relatively low amounts of mesoporous carbon black on the decomposition and reforming processes of hydrogen storage material NaAlH4 through in situ diffraction. The results show that even with low concentrations, mesoporous carbon black can significantly enhance the reversibility of hydrogen storage in NaAlH4.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Physics, Condensed Matter
Noel Jakse, Johannes Sandberg, Leon F. Granz, Anthony Saliou, Philippe Jarry, Emilie Devijver, Thomas Voigtmann, Jurgen Horbach, Andreas Meyer
Summary: Studying solidification process on the atomic scale requires accurate modeling of crystal nucleation or amorphization. This challenge is addressed by employing classical molecular dynamics simulations with a well-established high dimensional neural network potential trained on AIMD-generated configurations. The resulting potential is shown to accurately reproduce the structural and thermodynamic properties of liquid and undercooled states. Furthermore, investigations on a much larger scale reveal unique insights into nucleation mechanisms in different crystal phases.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Physics, Multidisciplinary
Hailong Peng, Huashan Liu, Thomas Voigtmann
Summary: Collective motion and length scales are important in the vitrification process of liquids. The study shows that both static and dynamic length scales play a role in the dynamics of vitrifying films. The temperature evolution of the dynamic correlation length exhibits a nonmonotonic behavior, which is related to the morphological change of cooperative rearrangement regions and the decoupling of fast-particle motion from bulk relaxation.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Luis F. Elizondo-Aguilera, Tommaso Rizzo, Thomas Voigtmann
Summary: This study demonstrates the presence of nonequilibrium scaling laws for the aging and equilibration dynamics in glass formers, which result from combining a relaxation equation for static structure with the equilibrium scaling laws of glassy dynamics. Different scaling regimes are predicted for the evolution of the structural relaxation time with age, depending on the depth of the quench.
PHYSICAL REVIEW LETTERS
(2022)
Article
Instruments & Instrumentation
Olfa D'Angelo, Felix Kuthe, Kasper van Nieuwland, Clint Ederveen Janssen, Thomas Voigtmann, Maziyar Jalaal
Summary: We present a setup for systematic studies on droplet spreading of complex fluids under microgravity conditions. By adjusting the gravitational acceleration, different spreading dynamics regimes can be accessed. The experimental module allows for the deposition of droplets and offers multiple observation and analysis methods under microgravity.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Article
Multidisciplinary Sciences
Christian Neumann, Johannes Thore, Melanie Clozel, Jens Guenster, Janka Wilbig, Andreas Meyer
Summary: Additive manufacturing using metallic powders in microgravity has been proven feasible through several sounding rocket flights, paving the way for future tests in prolonged microgravity settings. This advancement is crucial for space exploration beyond low Earth orbit.
Article
Chemistry, Multidisciplinary
Sandeep K. Gupta, Hannah H. Nielsen, Andreas M. Thiel, Emil A. . Klahn, Erxi Feng, Huibo B. Cao, Thomas C. Hansen, Eddy Lelievre, Arsen Gukasov, Iurii Kibalin, Sebastian Dechert, Serhiy Demeshko, Jacob Overgaard, Franc Meyer, Franc Meyer
Summary: In this study, a highly anisotropic single-ion magnet (SIM) with stability under ambient conditions was synthesized and comprehensively characterized. The influence of the ligand field on the degeneracy and population of d-orbitals in a specific coordination environment was investigated, providing important insights for the rational design and enhancement of magnetic anisotropy in SIMs.
Article
Materials Science, Multidisciplinary
John M. Wilkinson, Stephen J. Blundell, Sebastian Biesenkamp, Markus Braden, Thomas C. Hansen, Kacper Koteras, Wojciech Grochala, Paolo Barone, Jose Lorenzana, Zoran Mazej, Gasper Tavcar
Summary: KAgF3 is a quasi-one-dimensional quantum antiferromagnet with interesting structural and magnetic transitions. At low temperatures, it orders as an A-type antiferromagnet with an ordered moment. Previous magnetometry study provides evidence for an intermediate phase at T-N1 < T < T-N2, but its nature remains unknown.
Article
Chemistry, Multidisciplinary
Daniel Risskov Sorensen, Andreas Ostergaard Drejer, Michael Heere, Anatoliy Senyshyn, Matthias Frontzek, Thomas Hansen, Christophe Didier, Vanessa K. Peterson, Dorthe Bomholdt Ravnsbaek, Mads Ry Vogel Jorgensen
Summary: In operando powder diffraction is a powerful tool for investigating battery electrode materials. While X-ray powder diffraction is routine, neutron powder diffraction is still less established. Researchers have developed a new electrochemical cell for in operando neutron powder diffraction that is easy to use and can cycle electrode materials under electrochemical conditions similar to standard laboratory cells.
Article
Materials Science, Multidisciplinary
N. Qureshi, H. E. Fischer, S. X. M. Riberolles, T. C. Hansen, M. Ciomaga Hatnean, O. A. Petrenko
Summary: In this study, we investigate the short-range magnetic spin correlations in two compounds of rare-earth strontium oxides using total-scattering powder neutron diffraction, reverse Monte Carlo simulations, and magnetic pair-distribution function analysis. The compounds exhibit a distorted honeycomb lattice, leading to significant geometrical frustration due to antiferromagnetic exchange between magnetic ions. The results demonstrate the ordering of the short-range spin correlations above the respective Néel temperatures, indicating the dominance of nearest and next-nearest interactions.
Article
Physics, Multidisciplinary
Qianhui Xu, Yi Liu, Sijie Hao, Jiahui Qian, Cheng Su, Chin-Wei Wang, Thomas Hansen, Zhendong Fu, Yixi Su, Wei Li, Guang-Han Cao, Yinguo Xiao, Wentao Jin
Summary: The ground-state magnetic structures of Eu2+ spins in RbEu(Fe1-xNix)(4)As-4 superconductors have been studied using neutron powder diffraction measurements. It is observed that the magnetic propagation vector of the Eu sublattice diminishes with increasing Ni doping, leading to a reduction in the rotation angle between neighboring Eu layers. The magnetic structure transitions from a helical modulation to a collinear ferromagnetic structure as the superconductivity is suppressed.
PHYSICAL REVIEW RESEARCH
(2022)
