Article
Computer Science, Artificial Intelligence
Ivan S. Novikov, Konstantin Gubaev, Evgeny Podryabinkin, Alexander Shapeev
Summary: This paper focuses on the technology of constructing machine-learning interatomic potentials through active learning in the MLIP package, addressing efficient methods for automatically sampling training sets, the impact of expanding training sets on prediction errors, and cost-effective setup of ab initio calculations. The MLIP package can be downloaded at https://mlip.skoltech.ru/download/.
MACHINE LEARNING-SCIENCE AND TECHNOLOGY
(2021)
Article
Chemistry, Physical
Jack K. Pedersen, Christian M. Clausen, Lars Erik J. Skjegstad, Jan Rossmeisl
Summary: High-entropy alloys (HEAs) are special materials in multi-metallic catalysts, and successful modeling of their catalytic activity can help find optimal catalysts. This study shows that approximating the ligand effect of the surrounding atoms around an adsorption site with a mean-field perturbation is effective, but it results in large discrepancies when predicting far from near-equimolar compositions. Therefore, local ligand models are more useful for finding optimal catalysts.
Article
Nanoscience & Nanotechnology
M. Petrik, Yu N. Gornostyrev, P. A. Korzhavyi
Summary: The study systematically investigated the interactions of alloying elements and vacancies with coherent interfaces of the theta' phase in Al-based alloys, revealing that the presence of vacancies in the interfacial Cu layer plays a crucial role in solute-interface interactions. The solute-interface interaction energies were found to be weaker for elements with closed or empty d-electron shells compared to d-transition metals. The roles of alloying elements and interface structure in the stability of theta' phase precipitates were analyzed in terms of electronic structure and atomic size contributions to interatomic bonding.
SCRIPTA MATERIALIA
(2021)
Article
Chemistry, Physical
Abhishek Kundu, Baishanal Mandal, Biplab Maji, Debashis Adhikari
Summary: This study investigates the solvent-dependent chemodivergence in the nitrile reduction reaction using density functional theory (DFT). The results reveal that a polar protic solvent, isopropanol, promotes the formation of secondary amines through proton hopping, while a nonpolar solvent, n-hexane, inhibits the reaction and leads to the formation of primary amines.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Materials Science, Multidisciplinary
Xun Sun, Hualei Zhang, Dong Wang, Qiaoyan Sun, Shuangshuang Zhao, Song Lu, Wei Li, Levente Vitos, Xiangdong Ding
Summary: TiNb-based SMAs have great potential in biomaterials, but high transition temperature and limited recoverable strain are issues. A first-principles method was used to systematically study recoverable strain and transition temperature, finding that Zr can decrease M-s considerably while maintaining lattice strain. A Ti24Nb25Zr24S24Al3 HEA was designed to have large recoverable strain and low transition temperature simultaneously.
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
Songge Yang, Guangchen Liu, Yu Zhong
Summary: In this study, the relative stability of FCC and BCC single crystals of Al-Co-Cr-Fe-Ni high entropy alloys was investigated using high-throughput ab initio modeling, and the reliability of the Valence Electron Concentration (VEC) criterion was verified. The results show that the VEC criterion is effective not only for stable structures but also for metastable structures. Additionally, a new VEC rule was proposed to improve the shortcomings of the old VEC criterion for compositions containing high concentrations of light-weight metals.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Panpan Wang, Qilong Cao, Yuwei You, Xiangshan Kong, Xuebang Wu, Changsong Liu
Summary: Intermetallic alloy ZrCo is a good material for storing tritium, but prone to disproportionation reactions. Alloying atoms are often added to restrain disproportionation reactions, with Ti, V, Cr, Mn, etc. increasing the substitution energy of He. Introducing alloy atoms can help fix the He atom in ZrCo and avoid the reduction in tritium purity.
Article
Nanoscience & Nanotechnology
Hanqing Yin, Aijun Du
Summary: This study proposes a new type of ternary alloy electrocatalyst (Heusler alloy) for N2RR and demonstrates its superior catalytic performance. By alloying Ru with Mn and Si, N-2 molecules can be effectively activated and the overpotential reduced. In addition, the alloy has a stronger adsorption of N-2 compared to protons and requires less energy for N2RR, making it less competitive for the hydrogen evolution reaction (HER). This work provides a wider range of excellent N2RR electrocatalysts in terms of both catalytic performance and economical cost.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Jing Shang, Congxin Xia, Chun Tang, Chun Li, Yandong Ma, Yuantong Gu, Liangzhi Kou
Summary: The bending deformation of AgBiP2Se6 monolayers can manipulate the polarization direction and domain size, significantly improving the ferroelectric stability. This mechano-ferroelectric coupling represents a new mechanism for stabilization and polarization flip in 2D ferroelectrics, with potential applications in next-generation non-volatile storage devices.
NANOSCALE HORIZONS
(2021)
Article
Chemistry, Multidisciplinary
Xin Xiang, Wei Wei, Zeng-Xia Zhao, Hong-Xing Zhang
Summary: The mechanism underlying the rhodium-(III)-catalyzed reaction of the C-H alkenylation/annulation reaction of salicylaldehydes with enynes was thoroughly investigated using DFT calculations. The study revealed that with acetate assistance, a stepwise S(N)2' cyclization, 1,3-Rh migration, beta-H elimination, and reductive elimination process occur. Substitution at C-alpha was also found to play a role in the reaction.
Article
Materials Science, Multidisciplinary
Ahd Louafi, Yassine Chaouche, Amira El Hassasna
Summary: This study theoretically investigated the structural, elastic, and dynamical properties of YP1-xSbx alloys using DFT, focusing on the effect of Sb concentration on lattice parameter, mechanical stability, and frequency modes. Born effective charges and dielectric constants were also evaluated with varying Sb concentration.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Xi Zhang, Sergiy Divinski, Blazej Grabowski
Summary: In this study, ab initio density-functional-theory calculations were used to investigate the vacancy formation and migration energies in HCP Al-Hf-Sc-Ti-Zr high entropy alloys (HEAs) and their subsystems. The temperature-dependent formation Gibbs energies and averaged atomic environments were obtained using the special quasi-random structure approach and statistical analysis. It was found that the temperature-dependent vacancy formation Gibbs energy had a negative configurational entropy contribution. The local cluster expansion technique was applied to explore extended vacancy migration phase spaces.
Review
Materials Science, Multidisciplinary
Yue Li, Jianhong Dai, Yan Song
Summary: Ti-Al alloys have good prospects in aerospace, automobile, and other fields due to their excellent mechanical properties. However, their practical applications are limited by the lack of high temperature oxidation resistance. Experimental and theoretical studies have been conducted to study the oxidation behaviors, with theoretical studies based on first principles calculations providing strong support for understanding oxidation mechanisms and designing anti-oxidation modification measures.
Article
Chemistry, Multidisciplinary
Piotr Ruszala, Maciej J. Winiarski, Malgorzata Samsel-Czekala
Summary: The electronic structures and microscopic electronic properties of novel La1_xTlxN rock-salt materials have been studied. La0.5Tl0.5N exhibits metallic character, while La0.75Tl0.25N is similar to LaSb and LaBi. Topologically non-trivial characteristics are expected in these nitride materials.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2021)
Article
Materials Science, Multidisciplinary
Qigui Yang, Par Olsson
Summary: Understanding the formation and evolution of Cu precipitates in Fe-based alloys is crucial for their hardening and embrittlement effects. This study presents a first-principles investigation of positron annihilation in Fe-Cu systems, accurately predicting the characteristics of various homogeneous and heterogeneous Cu precipitates. The theoretical results show excellent agreement with experimental data, enabling clear distinction of different Cu precipitate types and reasonable estimation of their sizes. This work enhances the understanding of early-stage Cu precipitation in Fe matrix.
Article
Materials Science, Multidisciplinary
D. Da Fonseca, F. Onimus, F. Mompiou, M. -C. Marinica, E. de Sonis, E. Clouet, T. Jourdan
Summary: This study investigates the influence of elastic properties of point defects on dislocation climb under stress and irradiation. The elastic dipole tensors and diaelastic polarizabilities of vacancies and self-interstitial atoms in aluminum are evaluated using density functional theory calculations. These parameters are then incorporated into a Monte Carlo code and a diffusion model to estimate the stress dependence of dislocation climb. The results show that both parameters have an influence on point defect absorption under stress, with the dipole tensor effect only being 5 times larger than the polarizability effect. Additionally, considering polarizability is necessary for simulations under applied stress.
Article
Materials Science, Multidisciplinary
Petr Grigorev, Alexandra M. Goryaeva, Mihai-Cosmin Marinica, James R. Kermode, Thomas D. Swinburne
Summary: Calculations of dislocation-defect interactions are difficult due to the limitations of ab initio simulations. Hybrid methods, such as linear-in-descriptor machine learning potentials, offer a solution by embedding ab initio simulations in an empirical medium. This allows for more accurate modeling of dislocation migration pathways and defect geometries.
Article
Materials Science, Multidisciplinary
Matti Lindroos, Napat Vajragupta, Janne Heikinheimo, Diogo Ribeiro Costa, Abhishek Biswas, Tom Andersson, Paer Olsson
Summary: A crystal plasticity model is proposed for modelling the mechanical behavior of polycrystalline UO2. The model includes a dislocation-density-based formulation with three slip families and their interactions. It is parametrized using single crystal and polycrystal experimental data and evaluated for yield point, strain hardening behavior, temperature and strain rate dependencies. The effect of porosity on homogenized macroscopic stress-strain behavior and stress/strain localization at the grain level is analyzed.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Multidisciplinary Sciences
Alexandra M. Goryaeva, Christophe Domain, Alain Chartier, Alexandre Dezaphie, Thomas D. Swinburne, Kan Ma, Marie Loyer-Prost, Jerome Creuze, Mihai-Cosmin Marinica
Summary: It has been commonly believed that defects in face-centred cubic metals form larger dislocation loops through the coalescence of interstitial dumbbells. However, this study reveals that interstitial atoms in these metals actually cluster into compact 3D inclusions of A15 Frank-Kasper phase before forming dislocation loops. These A15 nano-phase inclusions then act as a source for prismatic or faulted dislocation loops. This discovery provides a better understanding of the complex mechanisms behind interstitial defect formation in metals.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Anruo Zhong, Clovis Lapointe, Alexandra M. Goryaeva, Jacopo Baima, Manuel Athenes, Mihai-Cosmin Marinica
Summary: The elastic properties of tungsten, an important material in future energy systems, are investigated up to its melting temperature using a data-driven approach. A machine learning force field is combined with enhanced sampling techniques to achieve accurate predictions of the material's behavior. A Bayesian sampling scheme is proposed to overcome the computational limitations of the machine learning force field, resulting in improved convergence speed and overall accuracy. The proposed method allows for the prediction of tungsten's elastic properties in temperature ranges that cannot be explored experimentally, opening up new possibilities for studying finite-temperature material properties.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Physics, Multidisciplinary
M. Vedak, G. J. Ackland
Summary: We investigate how to measure and define the entropy of a simple chaotic system without assuming the ergodic hypothesis. An approach of converting collision history into binary digits is proposed. Three methods are used to demonstrate the non-randomness of collision-generated strings compared with random number generator created strings: Shannon entropy, diehard randomness tests, and compression percentage. The study shows that Shannon entropy fails to distinguish random from deterministic strings, while the Diehard test misidentifies collision-generated strings as random under certain conditions. However, the zlib and bz2 compression algorithms efficiently detect non-randomness and low information content, with compression efficiencies approaching 100% for infinite strings. Consequently, the "compression algorithm entropy" of this chaotic system is non-extensive, contradicting the extensive entropy determined by assuming ergodicity based on phase-space integrals.
JOURNAL OF PHYSICS COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Paul Lafourcade, Jean-Bernard Maillet, Christophe Denoual, Eleonore Duval, Arnaud Allera, Alexandra M. Goryaeva, Mihai-Cosmin Marinica
Summary: This study utilizes spectral descriptors to encode local atomic environments and build crystal structure classification models. The proposed simple classification model is effective in training with small databases and demonstrates inherent transferability. The method shows good accuracy in extreme conditions and is applied to Zirconium and Aluminum with specific cases.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Chemistry, Physical
Miriam Marques, Miriam Pena-Alvarez, Miguel Martinez-Canales, Graeme J. Ackland
Summary: We demonstrate that hydrogen in metal superhydride compounds can exist in two distinct states-atomic and molecular. At low pressures, additional hydrogen atoms form molecules with electronic states below the Fermi energy, resulting in low-symmetry structures with large unit cells. At high pressures, molecules become unstable and all hydrogens become atomic. This study uses density functional theory to compare BaH4 with other stoichiometries and cations, and shows that increased temperature and zero-point motion favor high-symmetry atomic states, with bond rearrangements occurring on a picosecond time scale.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
Kangming Li, Chu-Chun Fu, Maylise Nastar, Frederic Soisson
Summary: We propose an efficient approach to predict atomic diffusion in concentrated magnetic systems using kinetic Monte Carlo with ab initio parametrized models. We successfully predict and explain the weak composition dependence of diffusion coefficients in Fe-Ni alloys, revealing the role of magnetic disorder in the difference between paramagnetic and magnetic ground states.
Article
Materials Science, Multidisciplinary
S. van de Bund, G. J. Ackland
Summary: Lanthanum hydride is the highest temperature superconductor known, with competing covalent bonding at lower pressures. Previous calculations neglect finite temperature, nuclear wave function, and zero-point pressure, all of which play important roles in stabilizing cubic phase.
Article
Materials Science, Multidisciplinary
Arnaud Allera, Alexandra M. Goryaeva, Paul Lafourcade, Jean-Bernard Maillet, Mihai-Cosmin Marinica
Summary: Accurate structural analysis is crucial for understanding atomic-scale processes in materials, but traditional methods often face limitations when applied to systems with thermal fluctuations or defect-induced distortions. To address this, the authors propose a novel descriptor for encoding atomic environments into 2D images, which enables accurate analysis using Convolutional Neural Networks at a low computational cost.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Qigui Yang, Xingzhong Cao, Baoyi Wang, Ping Wang
Summary: This work presents a systematic theoretical study on the positron annihilation characteristics in transition metals and other elements, revealing the evolution patterns of these characteristics and demonstrating the effect of solute elements on defects. The results contribute to the understanding and identification of microstructures in alloys and compounds.
Article
Materials Science, Multidisciplinary
Liuming Wei, Jingwen Li, Yonggang Li, Qirong Zheng, Fan Cheng, Chuanguo Zhang, Jingyu Li, Gaofeng Zhao, Zhi Zeng
Summary: This study investigates the influence of He-V complexes on H behaviors on different W surfaces using DFT calculations. The results show that H dissolution is most difficult but H trapping is easiest on the W (110) surface, while the opposite is true on the W (111) surface. Moreover, the presence of He-V complexes increases the difficulty of H diffusion from bulk to surface and desorption.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Yan Meng, Song Zeng, Chen Chen, Chaowen Zhu, Huahai Shen, Xiaosong Zhou, Xiaochun Han
Summary: The characteristics of magnetron sputtered Cr coatings vary with different temperature, bias voltage, and pressure. Coatings with random orientation, good crystallinity, and small grain size exhibit favorable oxidation behavior, while coatings with strong (200) texture, poor crystallinity, and large grains have many intrinsic defects that are detrimental to the protection property of the Cr coatings.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Xinyuan Xu, Zefeng Yu, Wei-Ying Chen, Aiping Chen, Arthur Motta, Xing Wang
Summary: This study presents an automated approach for characterizing grain morphology in TEM images recorded during ion irradiation. By combining a machine learning model and a computer vision algorithm, comparable results to human analysis can be achieved with significantly reduced analysis time. Researchers can train their own models following the procedures described in this study to automate grain morphology analysis of their own TEM images.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Shihao Wu, Dong Wang, Yapei Zhang, Koji Okamoto, Marco Pellegrini, Wenxi Tian, Suizheng Qiu, G. H. Su
Summary: The oxidation and degradation mechanisms of Cr coating on Zr alloy cladding under high temperature steam atmosphere are summarized, and a mathematical analysis model is established to predict the changes in coating thickness. The model is applied in the analysis of structure evolution under different conditions.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
V. Diaz-Mena, J. de Prado, M. Roldan, I. Izaguirre, M. Sanchez, M. Rieth, A. Urena
Summary: The brazeability of a cupronickel alloy was evaluated as a filler alloy for high-temperature joining of tungsten to steel. The study investigated the brazing conditions and the impact of the selected filler on the joint quality using numerical software. The results showed different metallurgical interactions and diffusion phenomena between the filler alloy and the base materials at different temperatures. The study emphasized the importance of selecting a suitable filler to mitigate residual stresses in the joints.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Pengcheng Zhu, Yajie Zhao, Yan-Ru Lin, Jean Henry, Steven J. Zinkle
Summary: This study investigates the effect of heavy-ion irradiation on radiation hardening in high-purity binary alloy Fe18Cr. Nanoindentation testing and high-quality TEM imaging were conducted to extract hardness and microstructure information. The strength factor was accurately calculated based on the detailed TEM characterization of irradiated microstructures, and a refined hardening superposition method was applied to quantify the mechanical properties of ion-irradiated materials.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Bin Wu, Haixia Ning, Hanzhen Zhu, Jianjun Chen, Kang Wang, Daiyu Zhang, Fu Wang, Qilong Liao
Summary: This study discusses the effects of ZrO2 and B2O3 on the phase composition and properties of SAP-based glass-ceramics. The results show that ZrO2 addition improves the formation of NZP phase while restricting the crystallization of AlPO4 phases. The correct ratios of ZrO2 and B2O3 allow only the formation of NZP phase within the SAP glass.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Hwasung Yeom, Greg Johnson, Benjamin Maier, Tyler Dabney, Kumar Sridharan
Summary: Cr-Nb bilayer coatings were developed using cold spray deposition to improve the limiting operational temperature of Cr-coated Zr-alloy system. The coatings exhibited outstanding oxidation resistance at high temperatures and formed continuous intermetallic compound layers at the interfaces.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Padhraic L. Mulligan, Andrew T. Nelson, Chad M. Parish, Patrick A. Champlin, Xiang Chen, Daniel Morrall, Jason M. Harp
Summary: Environmental barrier coatings are being developed to reduce oxidation and embrittlement in Zr-based materials. Chromium nitride is a candidate for this application, but understanding its impact on irradiation-induced creep and microstructure is critical.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Dexuan Yan, Xinlei Cao, Ke Shen
Summary: This study investigated the purification mechanism of polycrystalline graphite by comparing IG-11 graphite with IG-110 nuclear grade graphite. The analysis revealed that metallic impurities in IG-11 were primarily segregated within graphite porosities, while IG-110 demonstrated a significant reduction in impurities. This research contributes to the development of innovative graphite purification techniques for greater purity and stronger oxidation resistance.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Wei Xu, Wei Peng, Lei Shi, Qi Sun
Summary: This paper investigates the oxidation and shape evolution of matrix graphite in high temperature gas-cooled reactors during air-ingress accidents. A reaction kinetics model is established and computational fluid dynamics with a dynamic mesh method is used to simulate the oxidation process. The results show that the geometric shape of graphite changes significantly with increasing flow rate, and the graphite pebbles tend to form a structure with a narrow front and wide tail.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Allison Harward, Casey Elliott, Michael Shaltry, Krista Carlson, Tae-Sic Yoo, Guy Fredrickson, Michael Patterson, Michael F. Simpson
Summary: This paper investigates the hygroscopic properties of eutectic LiCl-KCl absorbed into zeolite-4A. The study finds that water absorption and corrosion worsen with increasing salt loading. It also suggests that the salt can be stored in a non-inert atmosphere for a certain period of time.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Takaaki Koyanagi, Xunxiang Hu, Christian M. Petrie, Gyanender Singh, Caen Ang, Christian P. Deck, Weon-Ju Kim, Daejong Kim, James Braun, Yutai Katoh
Summary: This study provides critical experimental data on the effects of irradiation on the hermeticity of SiC composite cladding, finding that irradiation can cause a decrease in hermeticity and cracking, and coating the outer surface can mitigate the cracking issue.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
S. Krat, A. Prishvitsyn, Yu. Gasparyan
Summary: This study proposes a probabilistic and diffusion-based model to describe the co-deposition of multiple hydrogen isotopes with slowly grown metal layers. The model calculates the relative concentrations of different hydrogen isotopes in the co-deposited metal layers. It is found that if hydrogen isotopes have different detrapping energies, only the isotope with the highest detrapping energy shows a monotonic decrease in concentration with deposition temperature. Furthermore, the study evaluates the uncertainty of tritium concentration in the co-deposited layer based on the uncertainty in detrapping energy of tritium and deuterium, predicting a >10% tritium concentration uncertainty for a 0.01 eV difference.
JOURNAL OF NUCLEAR MATERIALS
(2024)
Article
Materials Science, Multidisciplinary
Tijo Vazhappilly, Arup Kumar Pathak
Summary: This study investigates the effect of Ce atom substitution in UO2 on its thermophysical properties using density functional theory. The results show that the Ce substitution levels and the oxidation state of Ce/U atoms strongly influence the band structure and specific heat capacity of the UO2 lattice. These findings provide important insights into the fuel properties of UO2 under reactor conditions.
JOURNAL OF NUCLEAR MATERIALS
(2024)