Article
Chemistry, Multidisciplinary
Gohar Ayub, Abdur Rauf, Mudasser Husain, Ali Algahtani, Vineet Tirth, Tawfiq Al-Mughanam, Abdulaziz H. Alghtani, Nourreddine Sfina, Nasir Rahman, Mohammad Sohail, Rajwali Khan, Ahmed Azzouz-Rached, Aurangzeb Khan, Nora Hamad Al-Shaalan, Sarah Alharthi, Saif A. Alharthy, Mohammed A. Amin
Summary: In this study, the properties of fluoroperovskites are computed and examined using density functional theory with different approximations. The lattice parameters and fundamental physical properties of TlXF3 (X = Be, Sr) ternary fluoroperovskite compounds are investigated. The results show that both compounds are insulators with stable and strong mechanical properties. Based on our computations, these compounds have potential applications in industry, providing a reference for future work.
Article
Chemistry, Physical
Juan J. J. Aucar, Alejandro F. F. Maldonado, Juan I. I. Melo
Summary: In this work, relativistic corrections to the electric field gradient (EFG) are presented, including spin-dependent corrections for the first time. The results show that these new corrections significantly improve the performance of the existing method and are in close agreement with calculations at the four-component Dirac-Hartree-Fock (4c-DHF) level. The accuracy of the EFG values obtained with this new method allows for the analysis of the electronic origin of relativistic effects using well-known nonrelativistic operators.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Aleksandr Gusev
Summary: In this study, changes in elastic constants c(ij) of nonstoichiometric disordered cubic titanium carbide within the homogeneity interval were evaluated for the first time using a semiempirical method. It was found that the elastic stiffness constants c(ij) of disordered TiCy decrease as the titanium carbide composition deviates from stoichiometry, and the Vickers hardness H-V of titanium carbide increases non-linearly with growing relative carbon content y.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Abu Bakar, Muhammad Salman Kiani, Rab Nawaz, Abdul Wahab
Summary: In this study, the effects of high pressure on various properties of perovskite oxides CsNbO3 in the cubic phase were investigated using the pseudopotential approach and Boltzmann transport theory. The results showed that CsNbO3 has a stable structure and thermoelectric performance under high pressure, and exhibits potential applications in sensors and optoelectronic devices.
Article
Chemistry, Multidisciplinary
L. Debache, Y. Medkour, F. Djeghloul, K. Haddadi, S. Berri, M. Kharoubi, N. Bouarissa, N. Guechi, A. Roumili
Summary: Ab initio calculations based on density functional theory are used to investigate the mechanical, electronic, optical and transport properties of Ca5Si2N6 and Sr5Ge2N6 nitrides. The results show that these compounds are thermodynamically stable, with Ca5Si2N6 having the best stability. The electronic properties reveal that these nitrides are semiconductors, with Ca5Si2N6 having a direct energy gap of 3.55 eV. The optical response analysis suggests potential applications for Ca5Si2N6 and Sr5Ge2N6, and the thermo-electric properties indicate that these nitrides are favorable candidates for thermoelectric applications at low and room temperatures.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2023)
Article
Materials Science, Multidisciplinary
Chuanying Li, Tao Fu, Hao Hu, Xianghe Peng
Summary: In this study, the ideal mechanical properties and sensitivity to point defects of high-entropy carbides (HECs) and their constituent transition metal carbides (TMCs) were comparatively investigated using first-principles calculations. The results showed that HECs are insensitive to point defects, while the introduction of carbon vacancy significantly weakens the mechanical properties of TMCs. The study revealed the importance of the interaction between lattice distortion and defects in improving the mechanical properties of HECs.
Article
Chemistry, Multidisciplinary
Nisar Ahmad Ganie, Shabir A. Mir, Dinesh C. Gupta
Summary: A thorough theoretical analysis using density functional theory (DFT) has been performed to investigate the general physical features of RbTaSi and RbTaGe alloys. It is found that these alloys have stable ferromagnetic phase and exhibit half-metallic nature, making them suitable for spintronic applications.
Article
Materials Science, Ceramics
L. Deillon, M. Fornabaio, G. Zagar, L. Michelet, A. Mortensen
Summary: Multi-component transition monocarbides of chosen compositions were prepared by arc-melting a pre-alloy of transition metals and cast iron. The hardness and modulus of the resulting iron-embedded carbide particles were directly measured using nanoindentation. The variations in modulus and hardness with composition suggest that valence electron concentration is not the sole predictor of optimal compositions for predicting carbide hardness and modulus.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
Article
Materials Science, Ceramics
Shijun Zhao
Summary: The study found that in high-entropy ceramic carbides, carbon typically exhibits the most significant local lattice distortion, which helps stabilize the ceramic materials. Local distortion affects charge transfer, mechanical properties, and thermodynamic properties of HECs, making them soft and ductile with high strength.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2021)
Article
Materials Science, Multidisciplinary
Murat Canli, Esin Ilhan, Nihat Arikan
Summary: This study conducted ab initio pseudopotential calculations on the structural, electronic, elastic, vibrational, and thermodynamic properties of the full-Heusler X2ScGa (X = Ir and Rh) alloys. The results revealed metallic behavior, mechanical stability, ductile structure, and anisotropic behavior in the alloys. Additionally, the alloys showed dynamic stability in the L2(1) phase and are potential candidates for industrial use.
MATERIALS TODAY COMMUNICATIONS
(2021)
Article
Materials Science, Ceramics
A. Farhadizadeh, J. Vlcek, J. Houska, S. Haviar, R. Cerstvy, M. Cervena, P. Zeman, M. Matas
Summary: We investigate the influence of nitrogen content on the functional properties, thermal stability, and oxidation resistance of Hf-Y-Si-B-C-N coatings. Ab-initio simulations are employed to understand the relationship between the experimentally obtained properties and the atomic and electronic structures of the coatings. The optimal nitrogen content in the plasma and coatings is identified, which surpasses the performance of previous high-temperature material Hf6Y2-Si29B12C2N45. These findings represent a step forward in achieving enhanced thermal stability and oxidation resistance while maintaining multiple functional properties.
CERAMICS INTERNATIONAL
(2023)
Article
Materials Science, Ceramics
Qian Chen, You Xie, Zhengxin Yan, Hengchang Wang, Fengying Fan, Jie Xu, Feng Gao
Summary: This study investigated nonstoichiometric rare-earth zirconate materials using first-principles calculations and solid-state reaction methods, and found that excess Gd3+ and Zr4+ can decrease the elastic properties and hardness of the materials, increase their ductility, and reduce the thermal conductivity.
CERAMICS INTERNATIONAL
(2023)
Article
Physics, Multidisciplinary
Souheyr Meziane
Summary: The properties of transition metal aluminides have been investigated using density functional theory and semiclassical Boltzmann transport theory. The results show that these compounds have good mechanical and elastic properties, making them suitable for energy storage applications.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Physics, Multidisciplinary
Jiuyu Sun, Cheng-Wei Lee, Alina Kononov, Andre Schleife, Carsten A. Ullrich
Summary: Linear-response time-dependent density-functional theory (TDDFT) can accurately describe excitonic features in the optical spectra of insulators and semiconductors. By utilizing real-time TDDFT, it is possible to model excitons and study femtosecond exciton dynamics following short-pulse excitations, with potential extensions into the nonlinear regime.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Applied
Peiju Hu, Xing Xie, Lingling Bai, Runqing Zhang, Xunjiang Zhang, Jiaying Sun, Huafeng Dong, Minru Wen, Fugen Wu
Summary: The stability of WC-type ReC has been found to be controversial. In this study, stable structures in the rhenium-carbon system were systematically searched and analyzed. Four stable phases were identified under the pressure range of 0-300 GPa, while WC-type ReC was found to be unstable. Among these structures, C2/m-Re3C, P2(1)/m-Re4C, and C2/m-Re5C2 were discovered to maintain stability under ambient pressure. Furthermore, P6(3)/mmc-Re2C exhibited the highest hardness of 31.5 GPa, followed by metastable P 6 over bar m 2-Re5C3 with a hardness of 29.3 GPa.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Ceramics
Christopher R. Weinberger, Gregory B. Thompson
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2020)
Article
Materials Science, Multidisciplinary
Xiaochuan Tang, Rofiques Salehin, Gregory B. Thompson, Christopher R. Weinberger
PHYSICAL REVIEW MATERIALS
(2020)
Article
Materials Science, Multidisciplinary
Ian N. Bakst, John T. Sypek, Sriram Vijayan, Shuyang Xiao, Mark Aindow, Seok-Woo Lee, Christopher R. Weinberger
Summary: In this study, DFT simulations combined with analytical models were used to investigate the impact of defects and temperature on the mechanical response of [001]-oriented compression of CaFe2As2. The experiments showed that the solution in which CaFe2As2 is grown and post-growth heat treatment can affect the mechanical response of the materials. The simulations revealed that FeAs and Fe precipitate out of Fe-rich CaFe2As2, influencing the actual precipitates with the formation of a low-energy coherent interface.
Article
Materials Science, Multidisciplinary
John T. Sypek, Sriram Vijayan, Ian Bakst, Shuyang Xiao, Matthew J. Kramer, Paul C. Canfield, Mark Aindow, Christopher R. Weinberger, Seok-Woo Lee
Summary: The micropillar compression experiments on [001]-oriented CaFe2As2 single crystals have shown the existence of superelasticity with a high elastic limit. The collapsed tetragonal phase transition, influenced by microstructure and temperature, is the main mechanism of superelasticity. Factors like vacancies and nanoprecipitates affect the mechanical behavior significantly, and the onset stress for the phase transition decreases with decreasing temperature.
Article
Materials Science, Multidisciplinary
Jacob P. Tavenner, Christopher R. Weinberger, Shawn P. Coleman, Garritt J. Tucker
Summary: Grain boundaries have a significant influence on the mechanical behavior and deformation of crystalline materials, with intergranular failure potentially being driven by grain boundary character. Atomistic modeling and simulations reveal that grain boundary decohesion behavior may be influenced by atomic environments and dynamics, rather than conventional macroscopic grain boundary descriptors.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Anik H. M. Faisal, Christopher R. Weinberger
Summary: The study on twin boundary structures in BCC transition metals revealed that the pure reflection twin boundary structure is unstable and three possible metastable structures exist instead. Density functional theory simulations showed differences in stability and energetic preference between Group 5 and Group 6 BCC metals. These findings explain the presence of cusps in the commonly reported twinning generalized stacking fault energy curves.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Jiangwei Wang, Anik H. M. Faisal, Xiyao Li, Youran Hong, Qi Zhu, Hongbin Bei, Ze Zhang, Scott X. Mao, Christopher R. Weinberger
Summary: This study investigates the atomistic level dynamics of twinning in BCC tungsten (W) nanowires using in situ nanomechanical testing. The results show that deformation twins in W nanowires have a minimum size of six-layers and grow in increments of approximately three-layers at a time, in contrast to the layer-by-layer growth of deformation twins in face-centred cubic metals. These findings reveal a strong competition between twinning and slip in W nanowires, with a transition size of around 40 nm. The insights provided by this work are important for understanding the plastic deformation in a broad class of BCC metals and alloys.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Bahrum Prang Rocky, Christopher R. Weinberger, Steven R. Daniewicz, Gregory B. Thompson
Summary: Pre-dispersion of nanoparticles using suitable surfactants followed by mechanical mixing in a solvent and high-energy mechanochemical processing can achieve uniform dispersion of carbide NPs in a metal matrix composite.
Article
Materials Science, Multidisciplinary
Rofiques Salehin, Gregory B. Thompson, Christopher R. Weinberger
Summary: This work systematically investigates the trapping and storage capabilities of transition metal carbides using density functional theory. It reveals a strong correlation between trap energy and valence electrons in the transition metal, and demonstrates that a lower carbon concentration leads to more hydrogen storage in transition metal carbides.
MATERIALS & DESIGN
(2022)
Article
Materials Science, Multidisciplinary
Xiaochuan Tang, Rofiques Salehin, Gregory B. Thompson, Christopher R. Weinberger
Summary: A micromechanics model was developed to evaluate the elastic binding energy between carbide precipitates and hydrogen interstitials. Using this model, it was found that hydrogen atoms are more likely to bind on the broad surfaces of coherent carbide precipitates, while semicoherent precipitates may have significant hydrogen binding capability and incoherent precipitates do not have this capability. Factors influencing the binding energies between hydrogen atoms and carbide precipitates were analyzed, providing insights into hydrogen trapping in steel-based materials.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Gabriel Plummer, Michel W. Barsoum, Christopher R. Weinberger, Garritt J. Tucker
Summary: MAX phases, layered ternary carbides and nitrides, deform plastically through basal slip systems. Basal dislocations play a crucial role in incipient plastic deformation and their core structures and mobilities have been studied using atomistic calculations. The weakly bonded A-layer significantly affects the core structure of dislocations, with some configurations exhibiting non-planar cores and lower mobility. Additionally, due to the unique stacking sequence and stacking faults, basal dislocations preferentially nucleate and glide as same-signed pairs on adjacent slip planes, dissociating into zonal dislocations over larger distances for increased mobility.
Article
Materials Science, Multidisciplinary
Xiaochuan Tang, Gregory B. Thompson, Kaka Ma, Christopher R. Weinberger
Summary: The thermodynamic stability of equiatomic mixed carbides, known as high entropy carbides (HECs), is investigated. The enthalpy of mixing is found to be as important as configurational mixing entropy in these compounds. The formation of these carbides is controlled by the competition between entropy and enthalpy.
COMPUTATIONAL MATERIALS SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Xiang Wang, Sixue Zheng, Chuang Deng, Christopher R. Weinberger, Guofeng Wang, Scott X. Mao
Summary: By using in situ nanomechanical testing combined with atomistic simulations, the formation mechanisms of a 5-fold twin in nanostructured metals, such as gold, have been elucidated. Sequential twinning slip in varying slip systems and decomposition of high-energy grain boundaries play important roles in the formation process. The complex stress state in the neck area can also cause the breakdown of Schmid's law and result in 5-fold twin formation.
Article
Materials Science, Ceramics
Brennan R. Watkins, Jessica J. Lopez, Xiao-Xiang Yu, Gregory B. Thompson, Christopher R. Weinberger
Summary: In this paper, the phase stability and mechanical properties of alloying the carbide and nitride of a group IVB transition metal are studied using density functional theory. The emphasis is on elastic and dislocation properties, with the HfC-HfN system as an example. The results show that alloying reduces slip resistance, stabilizes dislocations, and different strategies have different effects between metal and non-metal alloying.
Article
Engineering, Mechanical
Anik H. M. Faisal, Christopher R. Weinberger
Summary: By using atomistic simulations, this study reveals that the thickness of deformation twin nuclei in BCC transition metals is two layers, contradicting the previously proposed three layers. The atomic structures of the twin nuclei also vary among different transition metals.
INTERNATIONAL JOURNAL OF PLASTICITY
(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.
