Article
Chemistry, Physical
Yue Su, Shaozhi He, Jiong Wang, Donglan Zhang, Qing Wu
Summary: Nanostructured Guinier-Preston (GP) zones are crucial for the strength of Al-Mg-Si(-Cu) aluminum alloys. Through first-principles calculations, the relatively stable atomic structure and growth mechanism of GP zones were investigated. The study revealed that GP zones on the (100) plane consist of {MgSi} atomic layers without Al atoms, with a tendency to grow up to 2 nm. In the (100) growth direction, even numbers of {MgSi} atomic layers are energetically favorable, with the presence of Al atomic layers to mitigate lattice strain. The most energetically favorable GP-zones configuration is {MgSi}(2)Al-4, with a substitution sequence of Cu atoms during the aging process: Al ? Si ? Mg. The growth of GP zones is accompanied by an increase in Mg and Si solute atoms and a decrease in Al atoms. Point defects, such as Cu atoms and vacancies, show different tendencies in their occupation within GP zones, with Cu atoms segregating near the Al layer and vacancies being captured by the GP zones.
Article
Engineering, Mechanical
Xiaolin Song, Xuanran Fu, Meng Wang
Summary: Resource conservation and environmental protection have made lightweight materials like magnesium alloys essential for rail transit. This study investigates the structure and properties of the beta ' phase in Mg-RE (RE = Y, Gd, Tb, or Dy) alloys using first-principles calculations. The results show that these alloys are thermodynamically and mechanically stable, and the addition of RE improves their elastic moduli, especially Young's modulus. Moreover, Mg-RE alloys exhibit better hardness and elastic anisotropy compared to α-Mg, due to the strong metallic bonds between RE and Mg atoms.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Metallurgy & Metallurgical Engineering
Krishnamohan Thekkepat, Hyung-Seop Han, Ji-Won Choi, Seung-Cheol Lee, Eul Sik Yoon, Guangzhe Li, Hyun-Kwang Seok, Yu-Chan Kim, Jae-Hun Kim, Pil-Ryung Cha
Summary: This article presents a methodology to calculate the electrochemical potentials of intermetallic compounds and alloys, which can be used to predict and control the formation of galvanic cells and minimize corrosion. By tailoring the zinc composition in the Mg-3wt%Sr-xZn alloy, the galvanic corrosion is successfully minimized.
JOURNAL OF MAGNESIUM AND ALLOYS
(2022)
Article
Nanoscience & Nanotechnology
Julian Brodie, Maryam Ghazisaeidi
Summary: In this study, we calculated the Gibbs Free Energy of stacking faults relevant to (c+a) slip and the cross-slip energy barrier of (c+a) screw dislocations in Mg, Mg-Al, and Mg-Ca alloys using density functional theory and the quasiharmonic approximation. It was found that the pyramidal II stacking fault energy is lower than the pyramidal I in pure Mg for a large temperature range, while the opposite is true in alloys at all temperatures. The addition of Al and Ca significantly reduces the pyramidal I stacking fault energy at room temperature, aiding in the stabilization of pyramidal I dislocations.
SCRIPTA MATERIALIA
(2023)
Article
Nanoscience & Nanotechnology
Arya Chatterjee, Liang Qi, Amit Misra
Summary: The investigation used transmission electron microscope to study the formation of early-stage precipitation, revealing complex processes with strong fluctuations in precipitate types and formation mechanisms during natural-aging. The nucleation of GP-II was found to be related to GP-I through either 'separated' nucleation or in situ nucleation.
SCRIPTA MATERIALIA
(2022)
Article
Chemistry, Physical
Xinxin Dong, Bo Wei, Dominik Legut, Haijun Zhang, Ruifeng Zhang
Summary: Mg-Zn alloys are promising as biodegradable materials due to their excellent mechanical properties and biocompatibility, but their corrosion behavior poses challenges for biomedical applications. By constructing Pourbaix diagrams based on first principles, researchers found that different alloy compositions exhibit unique corrosion mechanisms, such as galvanic corrosion in Mg-rich alloys and Zn corrosion in Zn-rich alloys. The presence of Cl ions in the environment has also been shown to influence the corrosion behavior of the alloys, highlighting the importance of understanding the alloy's degradation mechanisms for future design improvements.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Anna Soper, Adam L. Shaw, Patrick L. J. Conway, Gregory S. Pomrehn, Michael Ferry, Lori Bassman, Aurora Pribram-Jones, Kevin J. Laws
Summary: In this study, a computationally efficient method is proposed to stabilize the lightweight and strong Mg-Sc bcc phase by adding rare earth elements. Experimental validation shows that the bcc phase is stabilized by the addition of Y or Er, but not by La, Ce, or Nd. This study suggests a method to predict the integration of ternary elements into binary systems.
COMPUTATIONAL MATERIALS SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Du Cheng, Kang Wang, Bi-Cheng Zhou
Summary: This study critically reviews the crystal structures and stabilities of phases in the Mg-Zn system and identifies three key unanswered questions. Using first-principles calculations, the atomic structures of GP zones are predicted, the structures of beta(1)' precipitates are provided, and the origin of the two distinct multiple orientations between the beta(2)' phase and the matrix is traced. A feasible precipitation sequence in Mg-Zn alloys is suggested.
Article
Materials Science, Multidisciplinary
A. Ektarawong, S. Khamkaeo, B. Alling, T. Bovornratanaraks
Summary: The mixing thermodynamics of antifluorite-structured Mg2Si1-xGex were investigated using first-principles calculations, revealing the ease of formation of single-phase random solid solutions of Mg2Si1-xGex from 50 K and above. At 0 K, there is a weak energy preference towards local phase segregation, while a small lattice misfit between Mg2Si and Mg2Ge contributes to the stable formation of Mg2Si1-xGex random solid solutions at low temperatures. These findings also suggest the thermodynamic and mechanical stability of these solid solutions, providing insight into the complete solubility of Mg2Ge in Mg2Si and vice versa at all temperatures where atomic diffusion is activated.
Article
Materials Science, Multidisciplinary
Chiraag Nataraj, Ruoshi Sun, Christopher Woodward, Axel van de Walle
Summary: This study investigates the effects of Al and Hf impurities on the (111) antiphase boundary energy of metastable FCC Co3W through ab initio calculations. The results show that sacrificial W compositions stabilize the L1(2) structure over a wider range of compositions than constant ratio compositions. Hf increases the APB energy far more than Al, particularly at higher concentrations, and at higher concentrations of Hf, Hf and W tend to segregate into alternating planes.
Article
Materials Science, Multidisciplinary
Wei Shao, Sha Liu, Javier LLorca
Summary: The whole Al-Li phase diagram is accurately predicted from first principles calculations and statistical mechanics, taking into account the effect of configurational and vibrational entropy. The predicted phase diagram shows excellent agreement with the experimental results in terms of stable and metastable phases, phase boundaries, and maximum stability temperature of line compounds. The methodology demonstrates that accurate phase diagrams of technologically important alloys can be obtained from first principles calculations.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Chemistry, Physical
Lorenzo Monacelli, Nicola Marzari
Summary: CsSnI3 is a promising ecofriendly solution for energy harvesting technologies, but it deteriorates in the air. This study reveals the thermodynamic stability between its black perovskite polymorph and yellow 1D double-chain structure, driven by large quantum and anharmonic ionic fluctuations. The simulations show remarkable agreement with experimental data and provide insights into the ground state and heat capacity of CsSnI3.
CHEMISTRY OF MATERIALS
(2023)
Article
Multidisciplinary Sciences
Scott D. Thiel, James P. S. Walsh
Summary: This study investigates the impact of high pressure on ZrC using density functional theory and alloy cluster expansion, revealing that high pressure can significantly reduce sub-stoichiometry and drive the system towards fully stoichiometric composition. The results demonstrate the significant role of pressure in controlling vacancies in ZrC.
ADVANCED THEORY AND SIMULATIONS
(2022)
Article
Materials Science, Multidisciplinary
Hailian Wang, Yunxuan Zhou, Quan Dong, Xianhua Chen, Jun Tan
Summary: This study investigates the thermodynamic, mechanical, and electronic properties of Mg-Al-Si ternary compounds using first-principle density functional theory. The results show that these compounds are dynamically and thermodynamically stable. Furthermore, the mechanical properties of these compounds are enhanced with decreasing Mg content, which is beneficial for increasing the stiffness of Mg alloys.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Materials Science, Multidisciplinary
Mark Fedorov, Jan S. Wrobel, Andrew J. London, Krzysztof J. Kurzydlowski, Chu-Chun Fu, Tonci Tadic, Sergei L. Dudarev, Duc Nguyen-Manh
Summary: Using exchange Monte Carlo (MC) simulations based on an ab initio-parameterized Cluster Expansion (CE) model, the phase stability of low-Cr Fe-Cr alloys was explored as a function of vacancy (Vac), carbon, and nitrogen content. It was found that the addition of a small amount of C or N in an alloy without vacancies resulted in the formation of ordered compounds containing high amounts of Cr, C, and N. Cr segregated to interstitial atoms and the concentration of Cr in Cr-rich clusters increased with the concentration of C and/or N. In the presence of vacancies, C and N aggregate to the core regions of vacancy clusters, reducing the segregation of Cr-rich clusters. The structure of Cr-rich clusters varied depending on the concentration of interstitial atoms and the ratio of N to C. The predictions derived from MC simulations were in agreement with experimental observations of Fe-Cr alloys exposed to ion irradiation.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Multidisciplinary Sciences
Eric R. Hoglund, De-Liang Bao, Andrew O'Hara, Sara Makarem, Zachary T. Piontkowski, Joseph R. Matson, Ajay K. Yadav, Ryan C. Haislmaier, Roman Engel-Herbert, Jon F. Ihlefeld, Jayakanth Ravichandran, Ramamoorthy Ramesh, Joshua D. Caldwell, Thomas E. Beechem, John A. Tomko, Jordan A. Hachtel, Sokrates T. Pantelides, Patrick E. Hopkins, James M. Howe
Summary: As the size of materials decreases, the heterogeneities at interfaces become as significant as the surrounding materials. This study demonstrates the localized vibrational response of interfaces in strontium titanate-calcium titanate superlattices. The local structure at the interfaces creates phonon modes that determine the overall vibrational response of the superlattice when the spacing of the interfaces approaches the spatial extent of phonons.
Article
Thermodynamics
Kevin J. Meisner, Rahim Zaman, Bi-Cheng Zhou
Summary: In this study, CALPHAD thermodynamic models of the Ta-O system were developed using experimental data and first-principles calculations. The models accurately represent the equilibrium polymorphs of Ta2O5 and the O solubility in BCC Ta. Preliminary models for the liquid Ta-O phase were also developed. The calculated phase diagrams are consistent with existing experimental data.
CALPHAD-COMPUTER COUPLING OF PHASE DIAGRAMS AND THERMOCHEMISTRY
(2022)
Article
Multidisciplinary Sciences
Kiumars Aryana, John A. Tomko, Ran Gao, Eric R. Hoglund, Takanori Mimura, Sara Makarem, Alejandro Salanova, Md Shafkat Bin Hoque, Thomas W. Pfeifer, David H. Olson, Jeffrey L. Braun, Joyeeta Nag, John C. Read, James M. Howe, Elizabeth J. Opila, Lane W. Martin, Jon F. Ihlefeld, Patrick E. Hopkins
Summary: Materials with tunable thermal properties are crucial for the development of solid-state refrigeration, energy scavenging, and thermal circuits. This study demonstrates the bidirectional switching of thermal conductivity in antiferroelectric PbZrO3 by manipulating phonon scattering rates. PbZrO3 shows potential as a fast, repeatable, simple trigger, and reliable thermal switch.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Samantha T. Jaszewski, Eric R. Hoglund, Anna Costine, Marc H. Weber, Shelby S. Fields, Maria Gabriela Sales, Jaykumar Vaidya, Leah Bellcase, Katie Loughlin, Alejandro Salanova, Diane A. Dickie, Steven L. Wolfley, M. David Henry, Jon -Paul Maria, Jacob L. Jones, Nikhil Shukla, Stephen J. McDonnell, Petra Reinke, Patrick E. Hopkins, James M. Howe, Jon F. Ihlefeld
Article
Physics, Applied
Thomas W. Pfeifer, John A. Tomko, Eric Hoglund, Ethan A. Scott, Khalid Hattar, Kenny Huynh, Michael Liao, Mark Goorsky, Patrick E. Hopkins
Summary: In this study, a new method for analyzing the thermal conductivity variations in a material with spatial distribution of defects is developed using time-domain thermoreflectance. The near-surface thermal conductivity of silicon wafers irradiated with Kr+ ions is measured using this method. The results are validated using transmission electron microscopy, which confirms the spatial variation of the sub-surface silicon structure. The drastic reduction in silicon thermal conductivity is primarily attributed to structural defects and boundary scattering between amorphous and crystalline regions.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Du Cheng, Kang Wang, Bi-Cheng Zhou
Summary: This study critically reviews the crystal structures and stabilities of phases in the Mg-Zn system and identifies three key unanswered questions. Using first-principles calculations, the atomic structures of GP zones are predicted, the structures of beta(1)' precipitates are provided, and the origin of the two distinct multiple orientations between the beta(2)' phase and the matrix is traced. A feasible precipitation sequence in Mg-Zn alloys is suggested.
Article
Chemistry, Multidisciplinary
Eric R. R. Hoglund, De-Liang Bao, Andrew O'Hara, Thomas W. W. Pfeifer, Md Shafkat Bin Hoque, Sara Makarem, James M. M. Howe, Sokrates T. T. Pantelides, Patrick E. E. Hopkins, Jordan A. A. Hachtel
Summary: Grain boundaries are a common microstructural feature that greatly influence the functionality of various materials. Extensive experimental and theoretical studies have been conducted to understand the correlation between atomic-scale grain boundary structures and macroscopic properties. In this study, a SrTiO3 grain boundary was examined using advanced microscopy and spectroscopy techniques, along with density functional theory. The results provide insights into the impact of individual boundaries on macroscopic properties through the analysis of localized grain boundary vibrations.
ADVANCED MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Mackenzie J. Ridley, Kathleen Q. Tomko, John A. Tomko, Eric R. Hoglund, James M. Howe, Patrick E. Hopkins, Elizabeth J. Opila
Summary: Multi-component rare earth silicates offer a unique solution for simultaneously optimizing phase stability, thermo-chemical, and thermo-mechanical properties through variation of the rare earth elements implemented in the coating material.
Article
Chemistry, Physical
Kang Wang, Du Cheng, Bi-Cheng Zhou
Summary: Mixed-space cluster expansion (MSCE) is a first-principles method that can simultaneously model configuration-dependent short-ranged chemical and long-ranged strain interactions in alloy thermodynamics. This method has been successfully applied to binary FCC and BCC alloys. However, the previously reported MSCE method is limited to binary alloys with cubic crystal symmetry on a single sublattice. In this work, MSCE is generalized to systems with multiple sublattices by formulating compatible reciprocal space interactions and combined with a crystal-symmetry-agnostic algorithm for the calculation of constituent strain energy.
NPJ COMPUTATIONAL MATERIALS
(2023)
Proceedings Paper
Engineering, Mechanical
Du Cheng, Kang Wang, Bi-Cheng Zhou
Summary: In this study, the atomic structures and thermodynamic stabilities of precipitates in Mg-Sn and Mg-Zn alloys were investigated using first-principles calculations and cluster expansion. Potential Guinier-Preston (GP) zones were identified and the convergence behavior of Mg-Zn alloy was analyzed. These findings are important for the design of better age-hardened Mg alloys.
MAGNESIUM TECHNOLOGY 2022
(2022)
Article
Nanoscience & Nanotechnology
Jie Zhang, Xiaoyang Chen, MingJian Ding, Jiaqiang Chen, Ping Yu
Summary: This study enhances the compositional inhomogeneity of relaxor ferroelectric thin films to improve their dielectric temperature stability. The prepared films exhibit a relatively high dielectric constant and a very low variation ratio of dielectric constant over a wide temperature range.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Xiaoyu Chen, Ranran Zhang, Hao Zou, Ling Li, Qiancheng Zhu, Wenming Zhang
Summary: Polyaniline-manganese dioxide composites exhibit high conductivity, long discharge platform, and stable circulation, and the specific capacity is increased by providing additional H+ ions to participate in the reaction.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Xutao Huang, Yinping Chen, Jianjun Wang, Gang Lu, Wenxin Wang, Zan Yao, Sixin Zhao, Yujie Liu, Qian Li
Summary: This study aims to establish a novel approach to better understand and predict the behavior of materials with multi-scale lamellar microstructures. High-resolution reconstruction and collaborative characterization methods are used to accurately represent the microstructure. The mechanical properties of pearlite are investigated using crystal plasticity simulation and in-situ scanning electron microscopy tensile testing. The results validate the reliability of the novel strategy.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Cheng Chen, Fanchao Meng, Jun Song
Summary: This study systematically investigated the unfaulting mechanism of single-layer interstitial dislocation loops in irradiated L12-Ni3Al. The unfaulting routes of the loops were uncovered and the symmetry breaking during the unfaulting processes was further elucidated. A continuum model was formulated to analyze the energetics of the loops and predict the unfaulting threshold.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Darshan Bamney, Laurent Capolungo
Summary: This work investigates the formation of adjoining twin pairs (ATPs) at grain boundaries (GBs) in hexagonal close-packed (hcp) metals, focusing on the co-nucleation (CN) of pairs of deformation twins. A continuum defect mechanics model is proposed to study the energetic feasibility of CN of ATPs resulting from GB dislocation dissociation. The model reveals that CN is preferred over the nucleation of a single twin variant for low misorientation angle GBs. Further analysis considering GB character and twin system alignment suggests that CN events could be responsible for ATP formation even at low m' values.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Bing Han, Zhengqian Fu, Guoxiang Zhao, Xuefeng Chen, Genshui Wang, Fangfang Xu
Summary: This study investigates the behavior of electric-field induced antiferroelectric to ferroelectric (AFE-FE) phase transition and reveals the evolution of atomic displacement ordering as the cause for the transition behavior changing from sharp to diffuse. The novel semi-ordered configuration results from the competing interaction between long-range displacement modulation and compositional inhomogeneity, which leads to a diffuse AFE-FE transition while maintaining the switching field.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Akib Jabed, Golden Kumar
Summary: This study demonstrates that cryogenic rejuvenation promotes homogeneous-like flow and increases ductility in metallic glass samples. Conversely, annealing has the opposite effect, resulting in a smoother fracture surface.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Xin Ji, Yan Chong, Satoshi Emura, Koichi Tsuchiya
Summary: A heterogeneous microstructure in Ti-15Mo-3Al alloy with heterogeneous distributions of Mo element and omega(iso) precipitates has achieved a four-fold increase in tensile ductility without a loss of tensile strength, by blocking the propagation of dislocation channels and preventing the formation of micro-cracks.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Amit Samanta, Prasanna Balaprakash, Sylvie Aubry, Brian K. Lin
Summary: This study proposes a combined large-scale first principles approach with machine learning and materials informatics to quickly explore the chemistry-composition space of advanced high strength steels (AHSS). The distribution of aluminum and manganese atoms in iron is systematically explored using first principles calculations to investigate low stacking fault energy configurations. The use of an automated machine learning tool, DeepHyper, speeds up the computational process. The study provides insights into the distribution of aluminum and manganese atoms in systems containing stacking faults and their effects on the equilibrium distribution.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Guowei Zhou, Yuanzhe Hu, Zizheng Cao, Myoung Gyu Lee, Dayong Li
Summary: In this work, a physics-constrained neural network is used to predict grain-level responses in FCC material by incorporating crystal plasticity theory. The key feature, shear strain rate of slip system, is identified based on crystal plasticity and incorporated into the loss function as physical constitutive equations. The introduction of physics constraints accelerates the convergence of the neural network model and improves prediction accuracy, especially for small-scale datasets. Transfer learning is performed to capture complex in-plane deformation of crystals with any initial orientations, including cyclic loading and arbitrary non-monotonic loading.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Pengfei Yang, Qichang Li, Zhongying Wang, Yuxiao Gao, Wei Jin, Weiping Xiao, Lei Wang, Fusheng Liu, Zexing Wu
Summary: In this study, the HER performance of Ru-based catalysts is significantly improved through the dual-doping strategy. The obtained catalyst exhibits excellent performance in alkaline freshwater and alkaline seawater, and can be stably operated in a self-assembled overall water splitting electrolyzer.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Ilias Bikmukhametov, Garritt J. Tucker, Gregory B. Thompson
Summary: Depositing a Ni-1at. % P film can facilitate the formation of multiple quintuple twin junctions, resulting in a five-fold twin structure and a pentagonal pyramid surface topology. The ability to control material structures offers opportunities for creating novel surface topologies, which can be used as arrays of field emitters or textured surfaces.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Zening Yang, Weiwei Sun, Zhengyu Sun, Mutian Zhang, Jin Yu, Yubin Wen
Summary: Multicomponent oxides (MCOs) have wide applications and accurately predicting their thermal expansion remains challenging. This study introduces an innovative attention-based deep learning model, which achieves improved performance by using two self-attention modules and demonstrates adaptability and interpretability.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Ze Liu, Cai Chen, Yuanxun Zhou, Lanting Zhang, Hong Wang
Summary: This study attempts to address the gap in cooling rates between thin film deposition and bulk metallic glass (BMG) casting by correlating the glass-forming range (GFR) determined from combinatorial materials chips (CMCs) with the glass-forming ability (GFA) of BMG. The results show that the full-width at half maximum (FWHM) of the first sharp diffraction peak (FSDP) is a good indicator of BMG GFA, and strong positive correlations between FWHM and the critical casting diameter (Dmax) are observed in various BMG systems. Furthermore, the Pearson correlation coefficients suggest possible similarities in the GFA natures of certain BMG pairs.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Mike Schneider, Jean-Philippe Couzinie, Amin Shalabi, Farhad Ibrahimkhel, Alberto Ferrari, Fritz Koermann, Guillaume Laplanche
Summary: This work aims to predict the microstructure of recrystallized medium and high-entropy alloys, particularly the density and thickness of annealing twins. Through experiments and simulations, a database is provided for twin boundary engineering in alloy development. The results also support existing theories and empirical relationships.
SCRIPTA MATERIALIA
(2024)
