Computational Materials Science最新文献

{"title":"Simulation of stochastic discrete dislocation dynamics in ductile Vs brittle materials","authors":"Santosh Chhetri ,&nbsp;Maryam Naghibolhosseini ,&nbsp;Mohsen Zayernouri","doi":"10.1016/j.commatsci.2024.113541","DOIUrl":"10.1016/j.commatsci.2024.113541","url":null,"abstract":"<div><div>Defects are inevitable during the manufacturing processes of materials. Presence of these defects and their dynamics significantly influence the responses of materials. A thorough understanding of dislocation dynamics of different types of materials under various conditions is essential for analysing the performance of the materials. Ductility of a material is directly related with the movement and rearrangement of dislocations under applied load. In this work, we look into the dynamics of dislocations in ductile and brittle materials using simplified two dimensional discrete dislocation dynamics (2D-DDD) simulation. We consider Aluminium (Al) and Tungsten (W) as representative examples of ductile and brittle materials respectively. We study the velocity distribution, strain field, dislocation count, and junction formation during interactions of the dislocations within the domain. Furthermore, we study the probability densities of dislocation motion for both materials. In mesoscale, moving dislocations can be considered as particle diffusion, which are often stochastic and super-diffusive. Classical diffusion models fail to account for these phenomena and the long-range interactions of dislocations. Therefore, we propose the nonlocal transport model for the probability density and obtained the parameters of nonlocal operators using a machine learning framework.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113541"},"PeriodicalIF":3.1,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Data driven studies of magnetic ground state and transition temperature in two-dimensional magnets","authors":"Weidong Wang ,&nbsp;Runhu Xiao ,&nbsp;Shiwei Zhu ,&nbsp;Changsheng Song","doi":"10.1016/j.commatsci.2024.113542","DOIUrl":"10.1016/j.commatsci.2024.113542","url":null,"abstract":"<div><div>The magnetic characteristics of two dimensional (2D) van der Waals (vdW) magnets are governed by a delicate balance among various factors, posing a significant challenge in the design of novel 2D magnets. In this work, we employ a data-driven approach to investigate the magnetic properties of monolayers composed A₂B₂X₆, building upon the well-established ferromagnetic Cr₂Ge₂Te₆. Here, using random forest and gradient lift regression algorithms, we perform a high-throughput scan of 696 materials from a database to classify ferromagnetic and antiferromagnetic compounds based on their magnetic ground state. First principles-based computations and Monte Carlo simulations, followed by Heisenberg model-based, are employed to estimate the transition temperature (<span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>) of these magnets. The classification accuracy reaches approximately 84%, while the regression accuracy is around 81%. Our results not only enrich the family of 2D magnets and present high-temperature ferromagnetic materials but also offer insights into the realization of high temperature magnets. This work paves the way for accelerating the discovery of novel magnetic compounds with high transition temperatures for spintronic applications.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113542"},"PeriodicalIF":3.1,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atomic mechanisms of oxidative behavior of ferrochromium alloys by water-oxygen environment","authors":"Zongxiao Zhu ,&nbsp;Jialong Wang ,&nbsp;Dingfeng Qu ,&nbsp;Zhilong Zhao ,&nbsp;Hui Tan ,&nbsp;Qichun Sun ,&nbsp;Tao Zheng","doi":"10.1016/j.commatsci.2024.113567","DOIUrl":"10.1016/j.commatsci.2024.113567","url":null,"abstract":"<div><div>The formation of chromium-rich oxide layers on the surface of Fe-Cr alloys significantly impacts their performance at elevated temperatures. Understanding the formation process of these oxide layers at the atomic scale is crucial for further elucidating oxidation behavior, though it presents substantial challenges. In this study, ReaxFF molecular dynamics simulations were used to investigate the oxidation behavior of Fe-Cr alloys in high temperature water vapor and oxygen environments. The results demonstrate that chromium atoms are the primary contributors to the oxidation process, with Cr atoms diffusing to the surface more readily than iron atoms, leading to uneven stress distribution and creating high-stress regions near the Cr atoms. Additionally, hydrogen atoms generated from the breakdown of water molecules infiltrate the alloy matrix, promoting the creation, movement, and clustering of cation and anion vacancies, thereby enhancing oxidation reactions in high-temperature, humid conditions. The study further analyzes electron transfer during single-atom chemical reactions and explores the linear relationship between varying Cr content (10 %–30 %) and oxidation behavior under identical environmental conditions. These findings provide an important theoretical basis for optimizing the performance of Fe-Cr alloys for applications in high temperature environments.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113567"},"PeriodicalIF":3.1,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"N-body interatomic potential for molecular dynamics simulations of V-Cr-Nb-Mo-Ta-W system","authors":"V.N. Maksimenko ,&nbsp;A.G. Lipnitskii ,&nbsp;V.N. Saveliev ,&nbsp;A.I. Kartamyshev ,&nbsp;A.V. Vyazmin ,&nbsp;D.O. Poletaev","doi":"10.1016/j.commatsci.2024.113533","DOIUrl":"10.1016/j.commatsci.2024.113533","url":null,"abstract":"<div><div>Diffusion in high-entropy alloys is an important phenomenon controlling its evolution during exploitation. Its detailed investigation, especially at elevated temperatures, is a challenging task. Molecular dynamics simulations facilitate significantly findings in this area and provide valuable insights into it. The key part of the molecular dynamics is the interatomic potential representing the dependence of the potential energy of the system of atoms on their coordinates. To correctly calculate the diffusivity, the potentials should satisfy several criteria such as an accurate reproduction of the melting point and thermal expansion. The last one is crucial as diffusion is strongly influenced by the size factor. We used the N-body approach to construct the interatomic potential for the high-entropy alloy V-Cr-Nb-Mo-Ta-W system, which consists of the potentials for pure elements and binary systems constituting the six-component one. The constituting potentials reproduce structure, elastic, defect and melting properties of pure elements and concentration dependent properties of binary systems. As a test for the VNbMoTaW and VCrNbMoTaW alloys, we calculated the forces acting on atoms for a set of different compositions and obtained the adequate agreement with the density functional theory (DFT) results. Additionally, we computed the surface and excess screw dislocation energies for both pure elements and alloys. The experimental surface energy values averaged over the elements show remarkable agreement (less than 10%) for the equiatomic VNbMoTaW and VCrNbMoTaW alloys. The excess screw dislocation energies of pure elements are predicted in qualitative agreement with DFT results, with tungsten having the highest energy and vanadium and niobium having the lowest. The corresponding values for five- and six-component alloys are less than DFT ones with deviations of 7% and 34%, respectively. They are close or moderately less than the energies averaged over pure elements.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113533"},"PeriodicalIF":3.1,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrafast water diffusion along the interface between oxidized and pristine regions in graphene oxide: Reactive molecular dynamics study","authors":"Anastasia Zelenina ,&nbsp;Ekaterina V. Skorb ,&nbsp;Daria V. Andreeva ,&nbsp;Nikita Orekhov","doi":"10.1016/j.commatsci.2024.113461","DOIUrl":"10.1016/j.commatsci.2024.113461","url":null,"abstract":"<div><div>Graphene oxide (GO) is a promising membrane material due to its high water permeability. However, the exact physical mechanisms governing this process at the molecular level remain poorly understood, despite more than a decade of practical applications. In this article, we use classical molecular dynamics with the reactive potential ReaxFF to study the mobility of water molecules intercalated in GO and analyze the influence of its structure on diffusion processes. We highlight the previously unmentioned role of the interfacial area between oxidized and pristine graphene regions, which, according to our calculations, may be responsible for the ultrafast water transport observed in GO. This diffusion exhibits characteristics of a ballistic regime, suggesting another possible mechanism underlying GO’s high water permeability.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113461"},"PeriodicalIF":3.1,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural, electronic, and optical properties of two-dimensional bilayer MgCl2 intercalated with Be and Mg single atom: Insulator to semiconductor transformation","authors":"Nasir Shehzad ,&nbsp;Ismail Shahid ,&nbsp;Fazle Subhan ,&nbsp;Waheed-Ur-Rahman ,&nbsp;Meng-Qu Cai","doi":"10.1016/j.commatsci.2024.113468","DOIUrl":"10.1016/j.commatsci.2024.113468","url":null,"abstract":"<div><div>The intercalation of alkaline earth metals Be and Mg single atoms in the two-dimensional (2D) bilayer MgCl₂ (B-MgCl₂) system has been investigated in the present study, showing their effect on the structural, electronic, and optical characteristics using density functional theory (DFT) computation. The electronic behavior of B-MgCl₂ has been identified as that of an insulator. In contrast, the behavior of the Be and Mg-intercalated B-MgCl₂ shifts to that of a narrow band gap semiconductor, with the band gap measured at 1.00 eV and 0.98 eV for Be-MgCl₂ and Mg-MgCl₂, respectively. This notable change in electronic behavior presents intriguing opportunities for practical applications in optoelectronics and semiconductor devices. Moreover, the intercalation of Be and Mg atoms significantly influences the built-in electric field of the B-MgCl₂ system. The rise in the built-in electric field after the intercalation of Be and Mg atoms further emphasizes the potential for manipulating the electronic properties of this system for specific applications, potentially enabling improved charge transport and optoelectronic properties. Besides altering the electronic band structure, the intercalation of Be and Mg single atoms into the bilayer MgCl₂ system also induces prominent peaks in the infrared, visible, and ultraviolet (UV) regions of the solar spectrum. These observed optical characteristics represent a crucial aspect in the development of intercalation compounds for optoelectronic nanodevices, as they offer enhanced absorption and emission properties that can be harnessed in a wide range of technological applications and opening up avenues for innovation in the field of semiconductors.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113468"},"PeriodicalIF":3.1,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pressure waves induced by the bcc-hcp phase transition in dynamically loaded single crystal iron","authors":"N. Amadou ,&nbsp;T. de Rességuier","doi":"10.1016/j.commatsci.2024.113559","DOIUrl":"10.1016/j.commatsci.2024.113559","url":null,"abstract":"<div><div>Molecular Dynamics simulations have been used to investigate the dynamic response of single crystal iron to ramp compression along the [001] crystallographic direction, with a focus on the coupling between the propagation and interaction of pressure waves and the phase transformation process. In particular, we report an original observation at the atomic level of release and recompression waves specifically induced by the phase transition. We provide a straightforward, physically-based explanation of the origin of these waves based on impedance mismatch between the parent, daughter, and mixed-phase region, and show how they depend directly on the kinetics of the transformation. This analysis may be generalized to other time-dependent phase transformations in other materials subjected to dynamic loading, and it is probably still valid at the much larger space and time scales encountered in experiments, which could have practical implications.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113559"},"PeriodicalIF":3.1,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effects of biaxial strain and sulfur/boron doping on the photocatalytic performance of the g-C3N5 system: A first-principles study","authors":"Yongde Yao ,&nbsp;Fujian Tang ,&nbsp;Shangtong Yang","doi":"10.1016/j.commatsci.2024.113560","DOIUrl":"10.1016/j.commatsci.2024.113560","url":null,"abstract":"<div><div>Strain and doping are effective methods for enhancing the intrinsic properties of the photocatalyst g- C₃N₅. This paper investigates the electronic properties, optical characteristics, and changes in Gibbs free energy of g-C₃N₅ under the combined effects of biaxial strain and sulfur/boron (S/B) doping through first-principles calculations. By calculating the formation energy of the doping system, the optimal doping positions for B/S are identified. The results indicate that intrinsic g-C₃N₅ exhibits indirect band gap semiconductor properties with a band gap of 1.851 eV. In contrast, S/B doping reduces the band gap, with the S-doped g-C₃N₅ system (S-g-C₃N₅) displaying direct band gap semiconductor properties and a band gap of 1.677 eV. The application of tensile or compressive strain induces a red shift or blue shift in the absorption spectra of both the intrinsic g-C₃N₅ system and the doped system. Tensile strain positions the band edges of all systems favorably, enhancing carrier mobility and redox capability. This study provides valuable insights for the development of photocatalytic carbon nitride through atomic doping and strain modulation.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113560"},"PeriodicalIF":3.1,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Developing Mode I cohesive traction laws for crystalline Ultra-high molecular weight polyethylene interphases using molecular dynamics simulations","authors":"I.A. Mukherjee ,&nbsp;M.A.N. Dewapriya ,&nbsp;J.W. Gillespie Jr. ,&nbsp;J.M. Deitzel","doi":"10.1016/j.commatsci.2024.113552","DOIUrl":"10.1016/j.commatsci.2024.113552","url":null,"abstract":"<div><div>Ultra-high molecular weight polyethylene fiber with a diameter of 17 µm contains over 100,000 fibrils with diameters ranging from 10 to 100 nm. These fibrils can exhibit various relative rotations around the axial direction, forming interphases between distinct crystal planes. Fiber failure can occur due to defibrillation governed by the adhesion between fibrils. In this study, adhesion is quantified through cohesive traction laws that describe the strength, progressive damage, and energy absorption during fibril separation. We predict Mode I cohesive traction laws for polyethylene (PE) interphases between crystals with various orientations using molecular dynamics (MD) simulations. Results were compared with the stress-displacement response of perfect bulk crystals of similar thickness. Surface effects primarily manifested in the outermost layer of PE chains where molecular structure deviates from the bulk crystal structure resulting in a higher surface energy. This resulted in an interphase thickness equivalent to the thickness of two PE chain layers (1.2 nm). The disturbed crystal structure at the interfaces led to a 32% reduction in peak traction and a 46% reduction in energy absorption compared to the perfect bulk crystal. Additionally, results show that strain rate does not have an influence of the traction laws over the range of 10⁸ s⁻¹ to 10¹⁰ s⁻¹. The MD-based traction-separation relations were used to fit parameters for a cohesive zone model. The interphase traction laws predicted in this study can be used as interface properties to bridge length scales in multiscale simulations of defibrillation.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113552"},"PeriodicalIF":3.1,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Utilizing deep learning for swift analysis of high-throughput spectroscopic ellipsometry data on anodized oxides of valve metals","authors":"Xiaocha He ,&nbsp;Juan Zuo ,&nbsp;Wenhui Zhang ,&nbsp;Andrei Ionut Mardare ,&nbsp;Chaohui Guan ,&nbsp;Tenglei Han ,&nbsp;Dewei Zhao","doi":"10.1016/j.commatsci.2024.113549","DOIUrl":"10.1016/j.commatsci.2024.113549","url":null,"abstract":"<div><div>Spectroscopic ellipsometry is a powerful high-throughput method for mapping the optical properties of combinatorial anodic oxides on alloys. However, the traditional ellipsometry data fitting using non-linear regression highly depends on correct assumptions and is tedious. The determination of the transition concentration of parent alloys that influences its properties to change, based on existing experimental data, without requiring further experimental measurements is also crucial for alloy engineering. Herein, anodic oxides grown on Nb-Ta and Nb-Ti combinatorial thin film binary libraries using a co-sputtering process are prepared (Nb concentration range is 10 ∼ 90<!--> <!-->at.%, the oxidation voltage range is 1 ∼ 10 V). A deep learning method is developed to predict the refractive index (<em>n</em>) and extinction coefficient (<em>k</em>) of the oxide film from the ellipsometry data (606 groups). Four algorithms Convolutional Neural Networks (CNN), Convolutional Sequence-to-Sequence (ConvSeq2Seq), Temporal Convolutional Network (TCN), Gated Recurrent Unit Sequence-to-Sequence (GRUSeq2Seq) are compared. CNN achieves superior performance, yielding root mean square error values (RMSE) as low as 0.094 for predicting <em>n</em> and 0.037 for <em>k</em>. Additionally, a predictive model to reveal band-gap trends as a function of parent alloy composition and oxidation voltage at unmeasured locations along the libraries is developed. This approach helps identify the transition concentration that lead to optical property changes, thereby avoiding high experimental costs and potential experimental errors.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113549"},"PeriodicalIF":3.1,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}