Article
Chemistry, Multidisciplinary
Sophia L. Wandelt, Alexander Mutschke, Dmitry Khalyavin, Jennifer Steinadler, Wolfgang Schnick
Summary: Metal hydrides are a class of compounds that are used to create various functional materials. Neutron diffraction is necessary to study their structural characteristics due to the low scattering power of hydrogen for X-rays. In this study, a new strontium nitridoborate hydride, Sr-13[BN2](6)H-8, was synthesized and its crystal structure was determined using X-ray and neutron diffraction. The presence of anionic hydrogen within the structure was confirmed using MAS NMR and vibrational spectroscopy. Quantum chemical calculations supported the experimental findings. Sr-13[BN2](6)H-8 expands the family of nitridoborate hydrides and opens up possibilities for new and interesting materials.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Tiange Bi, Andrew Shamp, Tyson Terpstra, Russell J. Hemley, Eva Zurek
Summary: Evolutionary crystal structure prediction searches have revealed several metastable phases in the ternary Li-F-H system, with HnFn+1- anions and Li+ cations. The analysis of bonding within the HnFn+1- molecules, as well as the presence of other structural motifs such as LiF slabs and H3+ molecules in some structures, were conducted. The study also predicted the stability and properties of the different phases, including the insulators closest to the hull and the metallic LiF3H with a predicted vanishingly small superconducting critical temperature.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Review
Chemistry, Multidisciplinary
Meiling Xu, Yinwei Li, Yanming Ma
Summary: Pressure can induce the formation of new high-pressure phases and compounds with unconventional stoichiometries, leading to exotic physical and chemical properties. Recent studies have demonstrated the potential for developing new materials with specific desired properties under high pressure. Theory-oriented approaches have been successful in discovering compounds such as high-temperature superhydride superconductors, offering insights into the future direction of material design under high pressure.
Article
Chemistry, Physical
Volodymyr A. Yartys, Colin J. Webb, Fermin Cuevas
Summary: The paper provides an overview of advanced in situ diffraction studies for probing the structure and reacting mechanisms of hydrogen and energy storage materials. These studies utilize high flux diffraction beam and high resolution measurements to establish the mechanism of phase-structural transformations and their kinetics. Various conditions, such as hydrogen/deuterium pressures and temperatures, as well as different charge-discharge states, are considered. The paper also highlights the contributions of Dr. Michel Latroche and summarises a long-standing collaboration between the co-authors in the field.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Multidisciplinary Sciences
Wuhao Chen, Xiaoli Huang, Dmitrii V. Semenok, Su Chen, Di Zhou, Kexin Zhang, Artem R. Oganov, Tian Cui
Summary: This study successfully synthesized hcp-(La,Ce)H9-10 at 113GPa and observed high-temperature superconductivity at 176K and 100GPa, with an extrapolated upper critical field of 235T. The superconducting properties of La-Ce-H were significantly enhanced compared to the binary La-H and Ce-H compounds, indicating the potential of solid solution for improving superconductors.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Sumit Konar, Claire L. Hobday, Craig L. Bull, Nicholas P. Funnel, Qi Feng Chan, Angela Fong, Nurunnisa Atceken, Colin R. Pulham
Summary: A high-pressure neutron powder diffraction study and density functional theory calculations were conducted to investigate the structure and properties of perdeuterated para-xylene. The results demonstrate that para-xylene crystallizes in the monoclinic crystal system at low temperature, and the structural changes under pressure are minimal.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Chemistry, Physical
Ryan A. Klein, Rafael Balderas-Xicohtencatl, Jan Petter Maehlen, Terrence J. Udovic, Craig M. Brown, Robert Delaplane, Yongqiang Cheng, Roman Denys, Anibal J. Ramirez-Cuesta, Volodymyr A. Yartys
Summary: Intermetallic metal hydrides are essential for hydrogen storage, but those with higher storage capacities are still needed. Neutron vibrational spectroscopy (NVS) was used to study LaNiInHx and CeNiInH1.4, revealing close vibrational features between paired H atoms when x > 0.67. In contrast, no close H contacts were found in CeNiSnH, CeNiSnH2, and CeNiSnD2, demonstrating differences in hydrogen dynamics between the compounds.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Maxime Dottor, Jean-Claude Crivello, Laetitia Laversenne, Jean -Marc Joubert
Summary: The Hf-H(D) system was investigated using in situ neutron diffraction to understand its behavior under different compositions and temperatures. This study provided new insights into the phase existence and phase diagram of the system. Two major findings were the discovery of a new phase (gamma, PtS structure type) similar to the monohydride found in the H-Zr system, and the determination of the structure of the 6' phase, which is an ordered superstructure of the 6 phase (CaF2 structure type). Phase relations were established, and a new phase diagram was proposed.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
A. Herlihy, T. A. Bird, C. J. Ridley, C. L. Bull, N. P. Funnell, M. S. Senn
Summary: The local structure of high-pressure BaTiO3 has been investigated using neutron total scattering methods. The results suggest that the local structure behavior of BaTiO3 is affected by both temperature and pressure, which contrasts with its behavior at high temperature.
Article
Crystallography
Andre Goetze, Siobhan Christina Stevenson, Thomas Christian Hansen, Holger Kohlmann
Summary: Binary intermetallic compounds, such as FePd3, have attracted attention due to their physical, magnetic, and catalytic properties. In this study, the hydrogenation properties of ordered FePd3 and disordered Fe0.25Pd0.75 were investigated using various in situ methods. The results showed that FePd3 absorbs small amounts of hydrogen at room temperature and follows the Sieverts' law. The [Pd-6] octahedral voids were filled with hydrogen atoms as the hydrogen pressure increased, leading to a decrease in long-range order of Fe and Pd atoms. The magnetic moments of iron atoms in FePd3 exhibited a temperature dependence that was consistent with a 3D Ising or Heisenberg model.
Article
Materials Science, Multidisciplinary
Vedant K. Mehta, Sven C. Vogel, Aditya P. Shivprasad, Erik P. Luther, David A. Andersson, Dasari Rao, Dan Kotlyar, Bjorn Clausen, Michael W. D. Cooper
Summary: Various mechanical and thermophysical properties of YH2-x were studied using density functional theory calculations and neutron diffraction experiments. In the single-phase region, elastic constants and moduli increased with increasing hydrogen content. In the two-phase region, density was predicted to increase with decreasing H/Y due to the fraction of high-density Y metal.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Teng Ma, Yunyu Yin, Fang Hong, Pinwen Zhu, Xiaohui Yu
Summary: Bulk trigonal ε-Fe2N was sintered using high-pressure and high-temperature method, showing ferromagnetism with low coercive field, hardness of about 6.5 GPa, good thermal stability below 670 K, and excellent metal conductivity.
Article
Physics, Applied
Zhangyang Zhou, Leiming Fang, Zhengwei Xiong, Youjun Zhang, Yixuan Liu, Gaomin Liu, Yi Liu, Ruiqi He, Tiexin Han, Jun Li, Ke Wang, Zhipeng Gao
Summary: In this research, the high-pressure structural evolution of KNN was studied, revealing two structural phase transitions and determining the pressure range and path of the transitions. The output power density of KNN ceramic devices was comparable to that of commercially available PZT 95/5, but with only half the density, providing a significant advantage in terms of weight reduction and miniaturization of equipment.
APPLIED PHYSICS LETTERS
(2023)
Article
Multidisciplinary Sciences
Yan Zeng, Bin Ouyang, Jue Liu, Young-Woon Byeon, Zijian Cai, Lincoln J. Miara, Yan Wang, Gerbrand Ceder
Summary: Experiments demonstrate that using high-entropy metal cation mixes can improve the ionic conductivity of a compound, reduce reliance on specific chemistries, and enhance synthesizability. Local distortions introduced into high-entropy materials create an overlapping distribution of site energies for alkali ions, allowing them to percolate with low activation energy. This study provides important insights into selecting optimal distortion and designing high-entropy superionic conductors across a wide compositional space.
Article
Chemistry, Multidisciplinary
Song Wang, Zili Wu, Sheng Dai, De-en Jiang
Summary: A deep-learning approach has been proposed to accelerate the determination of hydride locations in metal nanoclusters, overcoming the challenges of utilizing neutron crystallography. The method demonstrates efficiency in predicting hydride locations in copper nanoclusters and has the potential to be applied to other metal systems.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Materials Science, Multidisciplinary
Volodymyr A. Yartys, Vasyl V. Berezovets, Ponniah Vajeeston, Lev G. Akselrud, Vladimir Antonov, Vladimir Fedotov, Steffen Klenner, Rainer Poettgen, Dmitry Chernyshov, Michael Heere, Anatoliy Senyshyn, Roman V. Denys, Ladislav Havela
Summary: Understanding the relationship between the structure, composition, and hydrogenation properties of intermetallic hydrides is crucial for improving their hydrogen storage performance. The ability to form hydrides and control their interaction with hydrogen is determined by their chemical composition. This study investigated a ScNiSn-based intermetallic hydride using various experimental techniques, including synchrotron and neutron powder diffraction, Mössbauer spectroscopy, hydrogenation, and thermal desorption spectroscopy. Computational calculations were also performed. The study revealed the mechanism of phase-structural transformation and the formation of unique metal-hydrogen bonding in the intermetallic alloy. At high pressures, a TiNiSi-type hydride was formed. The study also showed that scandium behaves similarly to the heavy rare earth metal holmium.
Article
Materials Science, Multidisciplinary
Iu. G. Morozov, O. V. Belousova, A. V. Safonov, M. V. Kuznetsov
Summary: Sb/Sb2O3 composite nanoparticles with average particle sizes ranging from 57 to 665 nm were synthesized using levitation-jet aerosol synthesis. XRD analysis confirmed the presence of rhombohedral Sb and cubic Sb2O3 crystal phases in the nanoparticles. It was discovered for the first time that these nanoparticles exhibit ferromagnetic behavior, with a maximum total magnetization of 0.053 emu/g. An excess paramagnetic susceptibility was also observed. The magnetic contributions at low temperature and room temperature vary depending on the average sizes of the nanoparticles, possibly due to localized states and interactions at the Sb/Sb2O3 interfaces on the nanoparticle surfaces.
MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS
(2023)
Article
Energy & Fuels
V Yartys, I Zavaliy, V Berezovets, Yu Pirskyy, F. Manilevich, A. Kytsya, Yu Verbovytskyy, Yu Dubov, A. Kutsyi
Summary: An autonomous power supply device based on a 30 W fuel cell stack and a hydrolysis-type hydrogen generator was developed. It included the construction of a hydrogen generation unit, development of an electronic control unit, and performance testing and optimization. The system efficiently generates H-2 using a flat type reactor with Pt catalyst deposited on cordierite as a support and a 10% solution of NaBH4. The electronic control unit effectively regulates the hydrolysis reaction rate and provides the required hydrogen supply to the fuel cell.
JOURNAL OF PHYSICS-ENERGY
(2023)
Article
Thermodynamics
J. M. Fiorani, M. Badran, J. M. Joubert, J. C. Crivello, A. A. A. P. da Silva, G. C. Coelho, C. A. Nunes, N. David, M. Vilasi
Summary: In this study, a new assessment of the Al-Nb system is presented using a combined first-principle and CALPHAD approach. The formation enthalpies of intermetallic phases were estimated from ab initio calculations. The liquid, fcc and bcc phases were described by a substitutional solution model, while the intermetallic phases D022 and A15 were described with the New Approach to the Compound Energy Formalism (NACEF). Different descriptions of the a phase were compared, and good agreement with experimental and ab initio data was achieved using a limited number of parameters. This work provides a self-consistent thermodynamic description of the Al-Nb system and demonstrates the compatibility of different descriptions using the NACEF approach.
CALPHAD-COMPUTER COUPLING OF PHASE DIAGRAMS AND THERMOCHEMISTRY
(2023)
Article
Chemistry, Physical
Nicolas Madern, Judith Monnier, Jean -Claude Crivello, Junxian Zhang, Karine Provost, Valerie Paul-Boncour, Solenn Reguer, Dominique Thiaudiere, Michel Latroche
Summary: Various applications benefit from lanthanides-3d metals compounds due to their fundamental physicochemical properties. To overcome raw material criticality and geopolitical tension, a better understanding of ternary systems is required. This study focuses on the Mn-Ni-Sm system, which is useful for energy storage applications. The combination of different techniques provides a better understanding of the physicochemical properties and phase equilibrium of this system, including the substitution of Mn atoms in the Ni sites.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Maxime Dottor, Jean-Claude Crivello, Laetitia Laversenne, Jean -Marc Joubert
Summary: The Hf-H(D) system was investigated using in situ neutron diffraction to understand its behavior under different compositions and temperatures. This study provided new insights into the phase existence and phase diagram of the system. Two major findings were the discovery of a new phase (gamma, PtS structure type) similar to the monohydride found in the H-Zr system, and the determination of the structure of the 6' phase, which is an ordered superstructure of the 6 phase (CaF2 structure type). Phase relations were established, and a new phase diagram was proposed.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
A. Moll, A. Hamidou, J. -C. Crivello, J. -M. Joubert, E. Alleno, C. Barreteau
Summary: We investigate the thermoelectric properties of SrCuX (X = P or Sb) using experiments and DFT calculations for the first time. Our calculations show that these stable and non-metallic compounds are suitable for thermoelectric applications. Experimental results confirm their non-metallic character, which is favorable for thermoelectricity.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Jean-Marc Joubert, Yordan Kalchev, Andrea Fantin, Jean-Claude Crivello, Rico Zehl, Erik Elkaim, Guillaume Laplanche
Summary: The site occupancies in a single-phase σ-intermetallic compound of composition Cr46Mn15.2Fe16.3Co17Ni5.5 (in at.%) were investigated using cutting-edge X-ray diffraction techniques, absorption spectroscopy, and simulations. The study found that the σ phase can accommodate a considerable degree of disorder, which has significant implications for thermodynamic modeling.
Article
Chemistry, Inorganic & Nuclear
Vitalii Shtender, Volodymyr Smetana, Jean-Claude Crivello, Lukasz Gondek, Janusz Przewozznik, Anja-Verena Mudring, Martin Sahlberg
Summary: This article reports the synthesis of two new ternary compounds, La15Ni13Bi5 and La9Ni8Sn5, through arc melting and annealing, and investigates their crystal structures and properties using single-crystal X-ray diffraction, first-principles calculations, and magnetic measurements.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Thomas Fernandes, Thomas Cavoue, Pascal Berger, Celine Barreteau, Jean-Claude Crivello, Nicolas Emery
Summary: In this study, the valence state of nickel ion in lamellar lithiated nitridonickelates was found to be close to +1.5, and a solid solution Li3-1.5xNixN was discovered. The attempt to introduce more nickel resulted in the presence of Li1.97Ni0.68N phase with metallic nickel as an impurity.
INORGANIC CHEMISTRY
(2023)
Editorial Material
Chemistry, Physical
Volodymyr A. Yartys, Fermin Cuevas
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Volodymyr A. Yartys, Colin J. Webb, Fermin Cuevas
Summary: The paper provides an overview of advanced in situ diffraction studies for probing the structure and reacting mechanisms of hydrogen and energy storage materials. These studies utilize high flux diffraction beam and high resolution measurements to establish the mechanism of phase-structural transformations and their kinetics. Various conditions, such as hydrogen/deuterium pressures and temperatures, as well as different charge-discharge states, are considered. The paper also highlights the contributions of Dr. Michel Latroche and summarises a long-standing collaboration between the co-authors in the field.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Shuvankar Gupta, Sudip Chakraborty, Vidha Bhasin, Santanu Pakhira, Shovan Dan, Celine Barreteau, Jean -Claude Crivello, S. N. Jha, Maxim Avdeev, Jean-Marc Greneche, D. Bhattacharyya, Eric Alleno, Chandan Mazumdar
Summary: In this paper, the successful synthesis and properties of a Fe-based highly spin-polarized quaternary Heusler alloy FeMnVGa are reported. Experimental and theoretical investigations reveal its high spin polarization (89.9%) and robustness of half-metallic ferromagnetic property in the presence of atomic disorder. The compound demonstrates great potential for spintronics applications.
Review
Energy & Fuels
Thabang R. Somo, Mykhaylo V. Lototskyy, Volodymyr A. Yartys, Moegamat Wafeeq Davids, Serge Nyallang Nyamsi
Summary: High entropy alloys (HEAs) formed by multi-principal elements show promising hydrogen storage performance. The properties of HEAs are related to their chemical composition and constituent elements, including electronegativity, atomic radii, and valence electron concentration. This review aims to clarify these features by performing systematic analysis of available experimental data. The analysis shows that valence electron concentration plays the most significant role in tuning the hydrogen storage performance of HEAs.
JOURNAL OF ENERGY STORAGE
(2023)
Article
Thermodynamics
Maxime Dottor, Jean-Claude Crivello, Jean -Marc Joubert
Summary: The phase diagram and thermodynamic data of the H-Nb system are evaluated and re-assessed to improve the description of this system. Experimental data reveals the solubility of niobium into the ε-ZrH2 phase, and Density Functional Theory calculations are used to determine the formation enthalpies of all the compounds and the mixing enthalpies in the different phases. Finally, a Calphad model for the H-Nb-Zr system is developed using literature data as well as experimental and calculated data.
CALPHAD-COMPUTER COUPLING OF PHASE DIAGRAMS AND THERMOCHEMISTRY
(2023)
Article
Materials Science, Multidisciplinary
Y. Liu, K. Zweiacker, C. Liu, J. T. McKeown, J. M. K. Wiezorek
Summary: The evolution of rapid solidification microstructure and solidification interface velocity of hypereutectic Al-20at.%Cu alloy after laser melting has been studied experimentally. It was found that the formation of microstructure was dominated by eutectic, alpha-cell, and banded morphology grains, and the growth modes changed with increasing interface velocity.
Article
Materials Science, Multidisciplinary
Bharat Gwalani, Julian Escobar, Miao Song, Jonova Thomas, Joshua Silverstein, Andrew Chihpin Chuang, Dileep Singh, Michael P. Brady, Yukinori Yamamoto, Thomas R. Watkins, Arun Devaraj
Summary: Castable alumina forming austenitic alloys exhibit superior creep life and oxidation resistance at high temperatures. This study reveals the mechanism behind the enhanced creep performance of these alloys by suppressing primary carbide formation and offers a promising alloy design strategy for high-temperature applications.
Article
Materials Science, Multidisciplinary
Jian Song, Qi Zhang, Songsong Yao, Kunming Yang, Houyu Ma, Jiamiao Ni, Boan Zhong, Yue Liu, Jian Wang, Tongxiang Fan
Summary: Recent studies have shown that achieving an atomically flat surface for metals can greatly improve their oxidation resistance and enhance their electronic-optical applications. Researchers have explored the use of graphene as a covering layer to achieve atomically flat surfaces. They found that high-temperature deposited graphene on copper surfaces formed mono-atomic steps, while annealed copper and transferred graphene on copper interfaces formed multi-atomic steps.
Article
Materials Science, Multidisciplinary
Jennifer A. Glerum, Jon-Erik Mogonye, David C. Dunand
Summary: Elemental powders of Al, Ti, Sc, and Zr are blended and processed via laser powder-bed fusion to create binary and ternary alloys. The microstructural analysis and mechanical testing show that the addition of Ti results in the formation of primary precipitates, while the addition of Sc and Zr leads to the formation of fine grain bands. The Al-0.25Ti-0.25Zr alloy exhibits comparable strain rates to Al-0.5Zr at low stresses, but significantly higher strain rates at higher stresses during compressive creep testing. Finite element modeling suggests that the connectivity of coarse and fine grain regions is a critical factor affecting the creep resistance of the alloys.
Article
Materials Science, Multidisciplinary
P. Jannotti, B. C. Hornbuckle, J. T. Lloyd, N. Lorenzo, M. Aniska, T. L. Luckenbaugh, A. J. Roberts, A. Giri, K. A. Darling
Summary: This work characterizes the thermo-mechanical behavior of bulk nanocrystalline Cu-Ta alloys under extreme conditions. The experiments reveal that the alloys exhibit unique mechanical properties, behaving differently from conventional nanocrystalline Cu. They do not undergo grain coarsening during extrusion and exhibit behavior similar to coarse-grained Cu.
Article
Materials Science, Multidisciplinary
Yiqing Wei, Jingwei Li, Daliang Zhang, Bin Zhang, Zizhen Zhou, Guang Han, Guoyu Wang, Carmelo Prestipino, Pierric Lemoine, Emmanuel Guilmeau, Xu Lu, Xiaoyuan Zhou
Summary: This study proposes a new strategy to modify microstructure by phase regulation, which can simultaneously enhance carrier mobility and reduce lattice thermal conductivity. The addition of Cu in layered SnSe2 induces a phase transition that leads to increased grain size and reduced stacking fault density, resulting in improved carrier mobility and lower lattice thermal conductivity.
Article
Materials Science, Multidisciplinary
Jia Chen, Zhengyu Zhang, Eitan Hershkovitz, Jonathan Poplawsky, Raja Shekar Bhupal Dandu, Chang-Yu Hung, Wenbo Wang, Yi Yao, Lin Li, Hongliang Xin, Honggyu Kim, Wenjun Cai
Summary: In this study, the structural origin of the pH-dependent repassivation mechanisms in multi-principal element alloys (MPEA) was investigated using surface characterization and computational simulations. It was found that selective oxidation in acidic to neutral solutions leads to enhanced nickel enrichment on the surface, resulting in reduced repassivation capability and corrosion resistance.
Article
Materials Science, Multidisciplinary
X. Y. Xu, C. P. Huang, H. Y. Wang, Y. Z. Li, M. X. Huang
Summary: The limited slip systems of magnesium (Mg) and its alloys hinder their wide applications. By conducting tensile straining experiments, researchers discovered a rate-dependent transition in the dislocation mechanisms of Mg alloys. At high strain rates, glissile dislocations dominate, while easy-glide dislocations dominate at low strain rates. Abundant glissile dislocations do not necessarily improve ductility.
Article
Materials Science, Multidisciplinary
M. S. Szczerba, M. J. Szczerba
Summary: Inverse temperature dependences of the detwinning stress were observed in face-centered cubic deformation twins in Cu-8at.%Al alloy. The detwinning stress increased with temperature when the pi detwinning mode was involved, but decreased when the pi/3 mode was involved. The dual effect of temperature on the detwinning stress was due to the reduction of internal stresses pre-existing within the deformation twins. The complete reduction of internal stresses at about 530 degrees C led to the equivalence of the critical stresses of different detwinning modes and a decrease in the yield stress anisotropy of the twin/matrix structure.
Article
Materials Science, Multidisciplinary
Taowen Dong, Tingting Qin, Wei Zhang, Yaowen Zhang, Zhuoran Feng, Yuxiang Gao, Zhongyu Pan, Zixiang Xia, Yan Wang, Chunming Yang, Peng Wang, Weitao Zheng
Summary: The interaction between the electrode and the electric double layer (EDL) significantly influences the energy storage mechanism. By studying the popular alpha-Fe2O3 electrode and the EDL interaction, we find that the energy storage mechanism of the electrode can be controlled by modulating the EDL.
Article
Materials Science, Multidisciplinary
Matthew R. Barnett, Jun Wang, Sitarama R. Kada, Alban de Vaucorbeil, Andrew Stevenson, Marc Fivel, Peter A. Lynch
Summary: The elastic-plastic transition in magnesium alloy Mg-4.5Zn exhibits bursts of deformation, which are characterized by sudden changes in grain orientation. These bursts occur in a coordinated manner among nearby grains, with the highest burst rate observed at the onset of full plasticity. The most significant burst events are associated with twinning, supported by the observation of twinned structures using electron microscopy. The bursts are often preceded and followed by a stasis in peak movement, indicating a certain "birth size" for twins upon formation and subsequent growth at a later stage.
Article
Materials Science, Multidisciplinary
Vaidehi Menon, Sambit Das, Vikram Gavini, Liang Qi
Summary: Understanding solute segregation thermodynamics is crucial for investigating grain boundary properties. The spectral approach and thermodynamic integration methods can be used to predict solute segregation behavior at grain boundaries and compare with experimental observations, thus aiding in alloy design and performance control.
Article
Materials Science, Multidisciplinary
Feiyu Qin, Lei Hu, Yingcai Zhu, Yuki Sakai, Shogo Kawaguchi, Akihiko Machida, Tetsu Watanuki, Yue-Wen Fang, Jun Sun, Xiangdong Ding, Masaki Azuma
Summary: This study reports on the negative and zero thermal expansion properties of Cd2Re2O7 and Cd1.95Ni0.05Re2O7 materials, along with their ultra-low thermal conductivity. Through investigations of their structures and phonon calculations, the synergistic effect of local structure distortion and soft phonons is revealed as the key to achieving these distinctive properties.
Article
Materials Science, Multidisciplinary
Thomas Beerli, Christian C. Roth, Dirk Mohr
Summary: A novel testing system for miniature specimens is designed to characterize the plastic response of materials for which conventional full-size specimens cannot be extracted. The system has an automated operation process, which reduces the damage to specimens caused by manual handling and improves the stability of the test results. The experiments show that the miniature specimens extracted from stainless steel and aluminum have high reproducibility, and the results are consistent with those of conventional-sized specimens. A correction procedure is provided to consider the influence of surface roughness and heat-affected zone caused by wire EDM.
Article
Materials Science, Multidisciplinary
Rani Mary Joy, Paulius Pobedinskas, Nina Baule, Shengyuan Bai, Daen Jannis, Nicolas Gauquelin, Marie-Amandine Pinault-Thaury, Francois Jomard, Kamatchi Jothiramalingam Sankaran, Rozita Rouzbahani, Fernando Lloret, Derese Desta, Jan D'Haen, Johan Verbeeck, Michael Frank Becker, Ken Haenen
Summary: This study investigates the influence of film microstructure and composition on the Young's modulus and residual stress in nanocrystalline diamond thin films. The results provide insights into the mechanical properties and intrinsic stress sources of these films, and demonstrate the potential for producing high-quality nanocrystalline diamond films under certain conditions.