Pub Date : 2024-11-23DOI: 10.1016/j.commatsci.2024.113548
J. Houska, M. Zhadko, R. Cerstvy, D. Thakur, P. Zeman
The non-equilibrium atom-by-atom growth of Cu-rich Cu-Zr thin films has been investigated by a combination of magnetron sputter deposition and molecular dynamics simulations. We focus on the role of Zr in the transition from large solid solution crystals through a nanocomposite (around ≈5 at.% Zr) to a metallic glass. We find, contrary to the assumption based on equilibrium phase diagram, that in this non-equilibrium case most of the grain refinement and most of the hardness enhancement (from 2.5 to 3 to 4–5 GPa) takes place in the compositional range (up to ≈3 at.% Zr) where many or even most Zr atoms (depending on the sputtering regime) are in the supersaturated solid solution rather than at the grain boundaries. The results are important for the design and understanding of technologically important nanostructured metallic films. In parallel, from the methodology point of view, the results include an early example of modelling the atom-by-atom nanocomposite growth.
{"title":"Role of Zr in Cu-rich single-phase and nanocomposite Cu-Zr: Molecular dynamics and experimental study","authors":"J. Houska, M. Zhadko, R. Cerstvy, D. Thakur, P. Zeman","doi":"10.1016/j.commatsci.2024.113548","DOIUrl":"10.1016/j.commatsci.2024.113548","url":null,"abstract":"<div><div>The non-equilibrium atom-by-atom growth of Cu-rich Cu-Zr thin films has been investigated by a combination of magnetron sputter deposition and molecular dynamics simulations. We focus on the role of Zr in the transition from large solid solution crystals through a nanocomposite (around ≈5 at.% Zr) to a metallic glass. We find, contrary to the assumption based on equilibrium phase diagram, that in this non-equilibrium case most of the grain refinement and most of the hardness enhancement (from 2.5 to 3 to 4–5 GPa) takes place in the compositional range (up to ≈3 at.% Zr) where many or even most Zr atoms (depending on the sputtering regime) are in the supersaturated solid solution rather than at the grain boundaries. The results are important for the design and understanding of technologically important nanostructured metallic films. In parallel, from the methodology point of view, the results include an early example of modelling the atom-by-atom nanocomposite growth.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113548"},"PeriodicalIF":3.1,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700034","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}
Pub Date : 2024-11-22DOI: 10.1016/j.commatsci.2024.113550
Shuai Li , Peng Li , Yixiao Jiang , Xiang Li , Sheng Zhang , Ziyi Sun , Tingting Yao , Chunlin Chen
To enhance the catalytic efficiency of titanium dioxide (TiO2), functioning as a wide-band semiconductor, it is necessary to facilitate the separation of photogenerated charges by modulating its band structure. We constructed (TiO2)n/LaAlO3 (n = 4–11) superlattice models and performed systematic first-principles calculations to investigate the modulation of the thickness of TiO2 on its band structure at interfaces. The results demonstrate that the electrostatic potential differences in the superlattices are higher for the odd layers of TiO2 than those for the even layers. On the other hand, the band gaps of TiO2 at interfaces are all lower than that in the bulk TiO2. As the thickness is increased from 4 to 11 layers, the band gap of TiO2 at the Al-O terminated interface shows a gradual increase. In contrast, the band gap of TiO2 at the La-O terminated interface exhibits fluctuations. These finds demonatrate the thickness and odd–even layers of TiO2 in TiO2/LaAlO3 superlattices can effectively modulate the built-in electric field and the band gap of TiO2 at interfaces.
{"title":"A first-principles study of band structure modulation at TiO2 heterogeneous interfaces","authors":"Shuai Li , Peng Li , Yixiao Jiang , Xiang Li , Sheng Zhang , Ziyi Sun , Tingting Yao , Chunlin Chen","doi":"10.1016/j.commatsci.2024.113550","DOIUrl":"10.1016/j.commatsci.2024.113550","url":null,"abstract":"<div><div>To enhance the catalytic efficiency of titanium dioxide (TiO<sub>2</sub>), functioning as a wide-band semiconductor, it is necessary to facilitate the separation of photogenerated charges by modulating its band structure. We constructed (TiO<sub>2</sub>)<sub>n</sub>/LaAlO<sub>3</sub> (n = 4–11) superlattice models and performed systematic first-principles calculations to investigate the modulation of the thickness of TiO<sub>2</sub> on its band structure at interfaces. The results demonstrate that the electrostatic potential differences in the superlattices are higher for the odd layers of TiO<sub>2</sub> than those for the even layers. On the other hand, the band gaps of TiO<sub>2</sub> at interfaces are all lower than that in the bulk TiO<sub>2</sub>. As the thickness is increased from 4 to 11 layers, the band gap of TiO<sub>2</sub> at the Al-O terminated interface shows a gradual increase. In contrast, the band gap of TiO<sub>2</sub> at the La-O terminated interface exhibits fluctuations. These finds demonatrate the thickness and odd–even layers of TiO<sub>2</sub> in TiO<sub>2</sub>/LaAlO<sub>3</sub> superlattices can effectively modulate the built-in electric field and the band gap of TiO<sub>2</sub> at interfaces.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113550"},"PeriodicalIF":3.1,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700029","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}
[Fe4S4] clusters have served as molecular batteries and charge transfer centers in many biosystems. However, their potential as electrode materials has been overlooked amidst the ever-increasing studies on various materials in the search for efficient battery compositions. To evaluate their electrochemical efficiency as electrode materials, we focused on the use of two important oxidation states, [Fe4S4]2+ and [Fe4S4]⁰, in a series of Li-, Na-, K-, Mg-, Ca-, and Zn-ion batteries. We also assessed the effect of metal–organic framework (MOF) formation on their performance by studying [Fe4S4]2+-1,4-benzenedithiolate MOF (BMOF) and its carboxylate-based counterpart (CMOF). Our model-based Density Functional Theory (DFT) calculations indicated that oxidation of the cluster to [Fe4S4]2+ and MOF formation significantly improve the electrochemical efficiency of the cluster. Among the studied electrode materials and metals, the BMOF combination with Mg0 and Zn2+ presented the best electrochemical performance. Notably, our periodic calculations indicated an open circuit voltage of 4.32 V for the Zn2+-BMOF system, suggesting a promising performance for BMOF compared to other cathode/negative electrode materials. Our atomic and electronic structure analyses indicated that intercalation is the underlying electrochemical mechanism.
{"title":"Metal-organic framework formation by [Fe4S4] clusters offers promising electrochemical performance","authors":"Fatemeh Keshavarz , Elham Mazarei , Atlas Noubir , Bernardo Barbiellini","doi":"10.1016/j.commatsci.2024.113551","DOIUrl":"10.1016/j.commatsci.2024.113551","url":null,"abstract":"<div><div>[Fe<sub>4</sub>S<sub>4</sub>] clusters have served as molecular batteries and charge transfer centers in many biosystems. However, their potential as electrode materials has been overlooked amidst the ever-increasing studies on various materials in the search for efficient battery compositions. To evaluate their electrochemical efficiency as electrode materials, we focused on the use of two important oxidation states, [Fe<sub>4</sub>S<sub>4</sub>]<sup>2+</sup> and [Fe<sub>4</sub>S<sub>4</sub>]⁰, in a series of Li-, Na-, K-, Mg-, Ca-, and Zn-ion batteries. We also assessed the effect of metal–organic framework (MOF) formation on their performance by studying [Fe<sub>4</sub>S<sub>4</sub>]<sup>2+</sup>-1,4-benzenedithiolate MOF (BMOF) and its carboxylate-based counterpart (CMOF). Our model-based Density Functional Theory (DFT) calculations indicated that oxidation of the cluster to [Fe<sub>4</sub>S<sub>4</sub>]<sup>2+</sup> and MOF formation significantly improve the electrochemical efficiency of the cluster. Among the studied electrode materials and metals, the BMOF combination with Mg<sup>0</sup> and Zn<sup>2+</sup> presented the best electrochemical performance. Notably, our periodic calculations indicated an open circuit voltage of 4.32 V for the Zn<sup>2+</sup>-BMOF system, suggesting a promising performance for BMOF compared to other cathode/negative electrode materials. Our atomic and electronic structure analyses indicated that intercalation is the underlying electrochemical mechanism.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113551"},"PeriodicalIF":3.1,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700030","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}
Pub Date : 2024-11-22DOI: 10.1016/j.commatsci.2024.113545
Sofia D. Melnikova, Sergey V. Larin
The effect of several key factors on the mechanical properties of multilayer polymer films under tensile and shear deformations was thoroughly investigated using atomistic molecular dynamics simulations. These factors included the composition of the layers, the compatibility of polymers in the layers, the crystallinity of polymers, and the thickness of the layers, especially when it decreases to values close to the radius of gyration (Rg) of the polymers. Three types of multilayer systems were considered: polylactide/poly(3-hydroxybutyrate) (PLA/PHB) based on polymers compatible for the selected chain lengths, polylactide/polyethylene (PLA/PE) with incompatible polymers in layers, and polylactide/polylactide (PLA/PLA). It was shown that reducing the layer thickness to the value close to Rg led to an increase in Young’s modulus for both types of systems with compatible polymers in layers PLA/PHB and with incompatible polymers PLA/PE. This effect was found for the systems composed of amorphous polymers. The influence of the layer thickness on shear modulus, yield stress under tensile and shear deformations was also analyzed. Young’s modulus and yield stress under tensile deformation were in line with the “rule of mixture” for all types of the systems. Both the shear modulus and yield stress under shear for PLA/PE tended to the values for bulk PE. Analysis of local atomic shear strain was employed to quantify local plastic deformations at the atomic level during the shear deformation. The pattern of local atomic shear strain distribution for the PLA/PHB and PLA/PLA systems was found to be significantly different from that for PLA/PE.
{"title":"Mechanical properties of the multilayer polymer films: Molecular dynamics simulations","authors":"Sofia D. Melnikova, Sergey V. Larin","doi":"10.1016/j.commatsci.2024.113545","DOIUrl":"10.1016/j.commatsci.2024.113545","url":null,"abstract":"<div><div>The effect of several<!--> <!-->key factors on the mechanical properties of multilayer polymer films<!--> <!-->under<!--> <!-->tensile and shear<!--> <!-->deformations was thoroughly investigated using atomistic molecular dynamics simulations. These factors included the composition of the layers, the compatibility of polymers in the layers, the crystallinity of polymers, and the thickness of the layers, especially when it decreases to values close to the radius of gyration (<em>R<sub>g</sub></em>) of the polymers. Three types of multilayer systems were considered: polylactide/poly(3-hydroxybutyrate) (PLA/PHB) based on polymers compatible for the selected chain lengths, polylactide/polyethylene (PLA/PE) with incompatible polymers in layers, and polylactide/polylactide (PLA/PLA). It was shown that reducing the<!--> <!-->layer<!--> <!-->thickness to the value close to <em>R<sub>g</sub></em> led to an increase in Young’s modulus for both types of systems with compatible polymers in layers PLA/PHB and with incompatible<!--> <!-->polymers PLA/PE. This effect was found for the systems composed of amorphous polymers. The influence of the layer thickness on shear modulus, yield stress under tensile and shear deformations was also analyzed. Young’s modulus and yield stress under tensile deformation were in line with the “rule of mixture” for all types of the systems. Both the shear modulus and yield stress under shear for PLA/PE tended to the values for bulk PE. Analysis of local atomic shear strain was employed to quantify local plastic deformations at the atomic level during the shear deformation. The pattern of local atomic shear strain distribution for the PLA/PHB and PLA/PLA systems was found to be significantly different from that for PLA/PE.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113545"},"PeriodicalIF":3.1,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700032","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}
Pub Date : 2024-11-22DOI: 10.1016/j.commatsci.2024.113532
Jesus A.M. Alvarenga , José A.S. Laranjeira , Guilherme S.L. Fabris , Julio R. Sambrano , Mario L. Moreira , Sergio S. Cava , Mateus M. Ferrer
This study investigates the ferroelectric phases of NaNbO3 using density functional theory (DFT) simulations. Special attention is given to the antiferroelectric polymorph Pbcm and the purported polar phases with monoclinic P1m1 and orthorhombic P21ma symmetries. The results reveal similarities in the diffraction patterns and Raman spectra of the P1m1 and P21ma models, while the Pbcm model exhibits greater distinctiveness. A comprehensive mechanical analysis was conducted, revealing notable anisotropy in mechanical properties and an unusually negative Poisson’s ratio for the R3c symmetry. In terms of ferroelectric properties, only the P1m1, P21ma, and R3c structures exhibit non-zero values for piezoelectric charge constants, indicating ferroelectric behavior. The Pbcm space group results from the stacking of two P21ma layers by a second-order improper rotation, explaining its antiferroelectric behavior. This work significantly contributes to the literature by providing a detailed understanding of the structural, vibrational, and mechanical properties of various NaNbO3 phases, highlighting the distinct ferroelectric and antiferroelectric behaviors.
{"title":"Investigating the ferroelectric phases of sodium niobate: A computational approach","authors":"Jesus A.M. Alvarenga , José A.S. Laranjeira , Guilherme S.L. Fabris , Julio R. Sambrano , Mario L. Moreira , Sergio S. Cava , Mateus M. Ferrer","doi":"10.1016/j.commatsci.2024.113532","DOIUrl":"10.1016/j.commatsci.2024.113532","url":null,"abstract":"<div><div>This study investigates the ferroelectric phases of NaNbO<sub>3</sub> using density functional theory (DFT) simulations. Special attention is given to the antiferroelectric polymorph <em>Pbcm</em> and the purported polar phases with monoclinic <em>P</em>1<em>m</em>1 and orthorhombic <em>P</em>2<sub>1</sub><em>ma</em> symmetries. The results reveal similarities in the diffraction patterns and Raman spectra of the <em>P</em>1<em>m</em>1 and <em>P</em>2<sub>1</sub><em>ma</em> models, while the <em>Pbcm</em> model exhibits greater distinctiveness. A comprehensive mechanical analysis was conducted, revealing notable anisotropy in mechanical properties and an unusually negative Poisson’s ratio for the <em>R</em>3<em>c</em> symmetry. In terms of ferroelectric properties, only the <em>P</em>1<em>m</em>1, <em>P</em>2<sub>1</sub><em>ma</em>, and <em>R</em>3<em>c</em> structures exhibit non-zero values for piezoelectric charge constants, indicating ferroelectric behavior. The <em>Pbcm</em> space group results from the stacking of two <em>P</em>2<sub>1</sub><em>ma</em> layers by a second-order improper rotation, explaining its antiferroelectric behavior. This work significantly contributes to the literature by providing a detailed understanding of the structural, vibrational, and mechanical properties of various NaNbO<sub>3</sub> phases, highlighting the distinct ferroelectric and antiferroelectric behaviors.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113532"},"PeriodicalIF":3.1,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700028","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}
Variability in the additive manufacturing process and powder material properties affect the microstructure which influences the macro-scale material properties. Systematic quantification and propagation of this uncertainty require numerous process-structure–property (P-S-P) simulations. However, the high computational cost of the P-S simulation (thermal model), which relates the microstructure to the process parameters, necessitates the need for inexpensive surrogate models. Moreover, the P-S simulation generates a high-dimensional microstructure image; this presents a challenge in constructing a surrogate model whose inputs are process parameters and output is the microstructure image. This work addresses this challenge and develops a novel approach to surrogate modeling. First, a dimension reduction method based on combining the concepts of image moment invariants and principal components is used to map the high-dimensional microstructure image into latent space. A surrogate model is then constructed in the low-dimensional latent space to predict the principal features, which are then mapped to the original dimension to obtain the microstructure image. The surrogate model-predicted microstructure image is verified against the original physics model prediction (thermal model + phase-field) of the microstructure image, using Hu moments. Developing this surrogate modeling approach paves the way for solving computationally expensive tasks such as uncertainty quantification and process parameter optimization.
增材制造工艺和粉末材料特性的不确定性会影响微观结构，而微观结构又会影响宏观材料特性。要系统地量化和传播这种不确定性，需要进行大量的工艺-结构-性能（P-S-P）模拟。然而，P-S 模拟（热模型）将微观结构与工艺参数联系起来，计算成本很高，因此需要廉价的替代模型。此外，P-S 模拟会生成高维微观结构图像；这对构建输入为工艺参数、输出为微观结构图像的代用模型提出了挑战。本研究针对这一挑战，开发了一种新颖的代理建模方法。首先，结合图像矩不变式和主成分的概念，采用降维方法将高维微观结构图像映射到潜在空间。然后在低维潜在空间中构建代用模型来预测主特征，再将主特征映射到原始维度，从而得到微观结构图像。代用模型预测的微观结构图像与原始物理模型（热模型 + 相场）预测的微观结构图像使用 Hu 矩进行验证。开发这种代用模型方法为解决计算昂贵的任务（如不确定性量化和工艺参数优化）铺平了道路。
{"title":"Surrogate modeling of microstructure prediction in additive manufacturing","authors":"Arulmurugan Senthilnathan , Paromita Nath , Sankaran Mahadevan , Paul Witherell","doi":"10.1016/j.commatsci.2024.113536","DOIUrl":"10.1016/j.commatsci.2024.113536","url":null,"abstract":"<div><div>Variability in the additive manufacturing process and powder material properties affect the microstructure which influences the macro-scale material properties. Systematic quantification and propagation of this<!--> <!-->uncertainty require numerous process-structure–property<!--> <!-->(P-S-P)<!--> <!-->simulations. However, the high computational cost of the P-S simulation (thermal model), which relates the microstructure to the process parameters, necessitates the need for inexpensive surrogate models. Moreover, the P-S simulation generates a high-dimensional microstructure image; this presents a challenge in constructing a surrogate model whose inputs are process parameters and output is the microstructure image. This work addresses this challenge and develops a novel approach to surrogate modeling. First, a dimension reduction method based on combining the concepts of image moment invariants and principal components is used to map the high-dimensional microstructure image into latent space. A surrogate model is then constructed in the low-dimensional latent space to predict the principal features, which are then mapped to the original dimension to obtain the microstructure image. The surrogate model-predicted microstructure image is verified against the original physics model prediction (thermal model + phase-field) of the microstructure image, using Hu moments. Developing this surrogate modeling approach paves<!--> <!-->the way for<!--> <!-->solving computationally expensive tasks such as uncertainty quantification and process parameter optimization.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113536"},"PeriodicalIF":3.1,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700027","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}
Pub Date : 2024-11-20DOI: 10.1016/j.commatsci.2024.113491
Mohammed A. Alsalman , Mahmoud S. Hezam , Saad M. Alqahtani , Ahmer A.B. Baloch , Fahhad H. Alharbi
Ionic radii play a key descriptor role in the field of material informatics and crystallography. Traditionally, improving the widely used Shannon’s radii dataset has primarily involved extending the cation radii since the original data was mostly cation-focused – thereby limiting its applicability. Accordingly, we have developed a method to estimate anion radii using a self-consistent calibration approach based on interatomic distances in binary compounds. This improvement shall enhance the precision of ionic radii-based descriptors, allowing for the exploration of a broader range of compounds beyond the usual oxides and fluorides. In this study, we conducted a detailed calibration protocol to enhance Shannon’s consolidated ionic radii table by integrating new anion entries and ensuring consistency with the established data. We employed a low-order regression model on the reference anions , , and to accurately estimate their radii in missing coordination numbers (five other points). These values proved crucial for recalibrating the set of key reference cations’ radii, which included , , , , , and , across coordination numbers 4, 6, and 8. We used recently updated and accurate interatomic distances from highly symmetric cubic binary structures in the Materials Project database to ensure this recalibration. Consequently, the adjusted cationic radii matched closely with Shannon’s original values, with deviations less than 5%, highlighting the accuracy of our approach. These calibrated cations were then used to derive new anion entries for binary and highly symmetric compounds expanding the data the database from 16 anion in Shannon’s to 33 in the proposed work. The implemented method resulted in 17 new anion configurations, namely , , , , , , , , , , , , , , , , and , and updated six existing configurations, namely , , , , , and . Our results have been integrated into Shannon’s updated ionic radii table, accessible at https://cmd-ml.github.io/, providing a robust data set for ongoing and future research in crystallography and materials engineering.
{"title":"Anions’ Radii — New data points calibrated to match Shannon’s table","authors":"Mohammed A. Alsalman , Mahmoud S. Hezam , Saad M. Alqahtani , Ahmer A.B. Baloch , Fahhad H. Alharbi","doi":"10.1016/j.commatsci.2024.113491","DOIUrl":"10.1016/j.commatsci.2024.113491","url":null,"abstract":"<div><div>Ionic radii play a key descriptor role in the field of material informatics and crystallography. Traditionally, improving the widely used Shannon’s radii dataset has primarily involved extending the cation radii since the original data was mostly cation-focused – thereby limiting its applicability. Accordingly, we have developed a method to estimate anion radii using a self-consistent calibration approach based on interatomic distances in binary compounds. This improvement shall enhance the precision of ionic radii-based descriptors, allowing for the exploration of a broader range of compounds beyond the usual oxides and fluorides. In this study, we conducted a detailed calibration protocol to enhance Shannon’s consolidated ionic radii table by integrating new anion entries and ensuring consistency with the established data. We employed a low-order regression model on the reference anions <figure><img></figure> , <figure><img></figure> , and <figure><img></figure> to accurately estimate their radii in missing coordination numbers (five other points). These values proved crucial for recalibrating the set of key reference cations’ radii, which included <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , and <figure><img></figure> , across coordination numbers 4, 6, and 8. We used recently updated and accurate interatomic distances from highly symmetric cubic binary structures in the Materials Project database to ensure this recalibration. Consequently, the adjusted cationic radii matched closely with Shannon’s original values, with deviations less than 5%, highlighting the accuracy of our approach. These calibrated cations were then used to derive new anion entries for binary and highly symmetric compounds expanding the data the database from 16 anion in Shannon’s to 33 in the proposed work. The implemented method resulted in 17 new anion configurations, namely <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , and <figure><img></figure> , and updated six existing configurations, namely <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , <figure><img></figure> , and <figure><img></figure> . Our results have been integrated into Shannon’s updated ionic radii table, accessible at <span><span>https://cmd-ml.github.io/</span><svg><path></path></svg></span>, providing a robust data set for ongoing and future research in crystallography and materials engineering.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113491"},"PeriodicalIF":3.1,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699789","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}
Pub Date : 2024-11-20DOI: 10.1016/j.commatsci.2024.113529
Xinyu He, Yingjiao Zhai, Jinhua Li, Fujun Liu
The internal atomic symmetry of the conventional two-dimensional (2D) semiconductor CdX is broken by constructing a Janus Cd2XY structure, and its fundamental spin–orbit coupling and spin mixing are investigated by the first-principles calculations. Further explained with a k·p model, it is found that the symmetry-broken Janus structure generates a built-in electric field to enable the generation of hybridized excitons and the conversion of dark- to bright- excitons. Our theoretical calculations are provided for the field-free approach in novel quantum information processing devices.
{"title":"Spin-mixing in Janus Cd2XY (X/Y = S, Se and Te) induced by Rashba SOC effect","authors":"Xinyu He, Yingjiao Zhai, Jinhua Li, Fujun Liu","doi":"10.1016/j.commatsci.2024.113529","DOIUrl":"10.1016/j.commatsci.2024.113529","url":null,"abstract":"<div><div>The internal atomic symmetry of the conventional two-dimensional (2D) semiconductor CdX is broken by constructing a Janus Cd<sub>2</sub>XY structure, and its fundamental spin–orbit coupling and spin mixing are investigated by the first-principles calculations. Further explained with a <em>k</em><strong><em>·</em></strong><em>p</em> model, it is found that the symmetry-broken Janus structure generates a <em>built-in</em> electric field to enable the generation of hybridized excitons and the conversion of dark- to bright- excitons. Our theoretical calculations are provided for the field-free approach in novel quantum information processing devices.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113529"},"PeriodicalIF":3.1,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699790","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}
Pub Date : 2024-11-20DOI: 10.1016/j.commatsci.2024.113530
Alexander Platonenko , Andrei Chesnokov , Kirill Chernenko , Vladimir Pankratov
Radiation resistant inorganic materials emitting cross-luminescence are one of the most prospective candidates for new generation ultrafast detectors for medical tomography. Radiative transitions leading to cross-luminescence occur between valence and core states, and therefore calculations of the electronic structure of doped materials can explain ultrafast transitions and predict new cross-luminescent materials. In current work we demonstrate results of ab initio calculations of undoped and doped BaF by means of hybrid density functional theory. As a result of the work, the density of states (DOS) for nominally pure BaF and a whole series of BaF doped with various trivalent ions were obtained. The positions of the core energy levels of dopant ions lying between the Ba(5p) zone and the F(2s) zone, as well local geometries and formation energies were calculated. Our calculations show that the 5p states of impurity ions can be located below the 5p zone of barium by several eV. This opens up opportunities for transitions from the core 5p Ba zone to impurity 5p states, which might be involved in experimentally observed appearance of an ultrafast component in doped BaF.
{"title":"Cross-luminescence in BaF2 crystals doped with M3+ and RE3+ ions: Hybrid density functional theory study","authors":"Alexander Platonenko , Andrei Chesnokov , Kirill Chernenko , Vladimir Pankratov","doi":"10.1016/j.commatsci.2024.113530","DOIUrl":"10.1016/j.commatsci.2024.113530","url":null,"abstract":"<div><div>Radiation resistant inorganic materials emitting cross-luminescence are one of the most prospective candidates for new generation ultrafast detectors for medical tomography. Radiative transitions leading to cross-luminescence occur between valence and core states, and therefore calculations of the electronic structure of doped materials can explain ultrafast transitions and predict new cross-luminescent materials. In current work we demonstrate results of <em>ab initio</em> calculations of undoped and doped BaF<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> by means of hybrid density functional theory. As a result of the work, the density of states (DOS) for nominally pure BaF<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and a whole series of BaF<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> doped with various trivalent ions were obtained. The positions of the core energy levels of dopant ions lying between the Ba(5p) zone and the F(2s) zone, as well local geometries and formation energies were calculated. Our calculations show that the 5p states of impurity ions can be located below the 5p zone of barium by several eV. This opens up opportunities for transitions from the core 5p Ba zone to impurity 5p states, which might be involved in experimentally observed appearance of an ultrafast component in doped BaF<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113530"},"PeriodicalIF":3.1,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700026","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}
Pub Date : 2024-11-18DOI: 10.1016/j.commatsci.2024.113544
Osman Furkan Yilmaz, Mesut Kirca
Three-dimensional graphene network (3DGN) material is a class of nanomaterials distinguished by their unique mechanical, electronic, and thermal properties, presenting an exciting platform in nanotechnology and materials science. With these properties, 3DGNs emerges as a promising candidate for diverse applications spanning electronics, catalysis, biomedicine, and beyond. The mechanical performance of 3DGN materials is significantly affected by their topology and geometry, emphasizing the significance of controlled geometrical modifications in tailoring the mechanical properties. In this study, our objective is to systematically investigate the effect of controlled geometrical modifications on the mechanical properties of 3DGN nanomaterials and offer the possibility of fine-tuning their mechanical properties. To this end, we performed numerical tensile tests via molecular dynamics (MD) simulations on a unique set of 720 3DGN specimens constructed by combining different triply periodic minimal surface (TPMS) geometries using a geometric hybridization technique. Our findings demonstrate that geometric hybridization can yield improvements in key mechanical properties such as Young’s modulus, ultimate strength and toughness compared to non-hybrid models. We also elucidated the underlying mechanisms governing the relationship between mechanical properties and hybridization and geometrical parameters. This study significantly advances the development of next-generation 3DGN nanomaterials across various fields by demonstrating the precise tunability of their mechanical properties through geometric design.
{"title":"Mechanical tuning of three-dimensional graphene network materials through geometric hybridization","authors":"Osman Furkan Yilmaz, Mesut Kirca","doi":"10.1016/j.commatsci.2024.113544","DOIUrl":"10.1016/j.commatsci.2024.113544","url":null,"abstract":"<div><div>Three-dimensional graphene network (3DGN) material is a class of nanomaterials distinguished by their unique mechanical, electronic, and thermal properties, presenting an exciting platform in nanotechnology and materials science. With these properties, 3DGNs emerges as a promising candidate for diverse applications spanning electronics, catalysis, biomedicine, and beyond. The mechanical performance of 3DGN materials is significantly affected by their topology and geometry, emphasizing the significance of controlled geometrical modifications in tailoring the mechanical properties. In this study, our objective is to systematically investigate the effect of controlled geometrical modifications on the mechanical properties of 3DGN nanomaterials and offer the possibility of fine-tuning their mechanical properties. To this end, we performed numerical tensile tests via molecular dynamics (MD) simulations on a unique set of 720 3DGN specimens constructed by combining different triply periodic minimal surface (TPMS) geometries using a geometric hybridization technique. Our findings demonstrate that geometric hybridization can yield improvements in key mechanical properties such as Young’s modulus, ultimate strength and toughness compared to non-hybrid models. We also elucidated the underlying mechanisms governing the relationship between mechanical properties and hybridization and geometrical parameters. This study significantly advances the development of next-generation 3DGN nanomaterials across various fields by demonstrating the precise tunability of their mechanical properties through geometric design.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":"247 ","pages":"Article 113544"},"PeriodicalIF":3.1,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700025","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}
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