Computational Materials Science最新文献_第7页

Impact of van der Waals corrected functionals on monolayer GeSe polymorphs: An in-depth exploration 范德华修正函数对单层 GeSe 多晶体的影响：深入探讨

IF 3.1 3区材料科学

Computational Materials Science Pub Date : 2024-09-21 DOI: 10.1016/j.commatsci.2024.113383

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Passivation effect of hydrogen and oxygen on the carrier capture of vacancies in 4H-SiC 氢和氧对 4H-SiC 中空位载流子捕获的钝化效应

IF 3.1 3区材料科学

Computational Materials Science Pub Date : 2024-09-21 DOI: 10.1016/j.commatsci.2024.113365

{"title":"Passivation effect of hydrogen and oxygen on the carrier capture of vacancies in 4H-SiC","authors":"","doi":"10.1016/j.commatsci.2024.113365","DOIUrl":"10.1016/j.commatsci.2024.113365","url":null,"abstract":"<div><div>Unintentional dopants, such as hydrogen and oxygen, are unavoidable in the epitaxial growth of semiconductors, significantly impacting the device performances by acting as traps for interstitials and passivation. Herein, hybrid functional was adopted to systematically investigate the charge transfer of vacancies altered by hydrogen and oxygen passivation in 4H-SiC. Overall, both of them stabilize the formation of vacancies to prevent the diffusion and recombination effectively. Especially, the more the hydrogen passivated, the lower the formation energies. The number of passivated hydrogens shows huge impacts on the hole capturing of carbide vacancy (V<sub>C</sub>), while the effect is small on carbon dangling bonds to capture electron both k and h site, of which the transition level ε (0/−1) always locates around E<sub>C</sub> − 0.3–0.6 eV. Silicon vacancy (V<sub>Si</sub>) primarily acts as an electron acceptor, with its transition level ε (0/−1) showing limited response to hydrogen passivation, while the effectiveness of electron capture is determined by the passivation process. Comparing divacancy (V<sub>C</sub>V<sub>Si</sub>) with single V<sub>C</sub> and V<sub>Si</sub>, there is an enhanced ability for hole capturing by silicon dangling orbitals. Once all dangling bonds are passivated, V<sub>C</sub>, V<sub>Si</sub> and V<sub>C</sub>V<sub>Si</sub> always keep neutral state. For oxygen passivation, V<sub>C</sub> turns to a donor with one oxygen passivation and a neutral defect with fully passivated. V<sub>Si</sub> is regulated from an acceptor to a bipolar dopant with one and two oxygen passivation. Our calculations unveil the underlying mechanism for hydrogen and oxygen passivation effects on the process of carrier captures of vacancies, which can further explain the relative defect signal in experimental characterizations.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312615","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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The effect of surface modification on the performance of graphene based honeycomb porous structure as Li-ion battery anode materials 表面改性对石墨烯基蜂窝多孔结构锂离子电池负极材料性能的影响

IF 3.1 3区材料科学

Computational Materials Science Pub Date : 2024-09-20 DOI: 10.1016/j.commatsci.2024.113395

{"title":"The effect of surface modification on the performance of graphene based honeycomb porous structure as Li-ion battery anode materials","authors":"","doi":"10.1016/j.commatsci.2024.113395","DOIUrl":"10.1016/j.commatsci.2024.113395","url":null,"abstract":"<div><div>In an effort to study the surface properties of 3D porous carbon anode materials for Li-ion batteries, the geometric and electronic structures, adsorption as well as diffusion characteristics of Li-ions on the surface of graphene based honeycomb porous structure with surface dangling bonds terminated by H or F atoms were calculated using first-principles calculations. It has been found that both of them are semiconductors with smaller band gaps, and F atoms termination can effectively reduce the energy barrier in diffusion processes and simultaneously augment the adsorption sites of Li-ions on the surface of hp16. For the surface of H termination, the energy barrier for Li-ions diffusing is about 1.8 eV. But for the surface of F termination, it drops to 0.45 eV. In the honeycomb pores of both structures, Li-ions have smaller diffusion barriers than in 3D hp16. The results of AIMD simulation indicate that fluorination of surface dangling bonds is more conducive to the diffusion of Li-ions on the surface, while hydrogenation hinders Li-ions diffusion. This discovery is of great significance for reducing the diffusion energy barrier of Li-ions on the surface of honeycomb porous structure as well as provides ideas for the advancement of carbon anode materials used for Li-ion batteries.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312693","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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Magnetic properties of a hollow sphere with mixed spins «1/2, 1, 3/2, 2» : A Monte Carlo simulations 具有 "1/2、1、3/2、2 "混合自旋的空心球的磁特性：蒙特卡罗模拟

IF 3.1 3区材料科学

Computational Materials Science Pub Date : 2024-09-20 DOI: 10.1016/j.commatsci.2024.113375

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First-principles study on the stability, electronic structure, and band alignment of AgNbO3 surfaces: Understanding the adsorption process of H2O and O2 关于 AgNbO3 表面稳定性、电子结构和能带排列的第一性原理研究：了解 H2O 和 O2 的吸附过程

IF 3.1 3区材料科学

Computational Materials Science Pub Date : 2024-09-20 DOI: 10.1016/j.commatsci.2024.113398

{"title":"First-principles study on the stability, electronic structure, and band alignment of AgNbO3 surfaces: Understanding the adsorption process of H2O and O2","authors":"","doi":"10.1016/j.commatsci.2024.113398","DOIUrl":"10.1016/j.commatsci.2024.113398","url":null,"abstract":"<div><div>In this work, DFT calculations have been employed to delve into the structural, electronic, and optical properties of low-index (010), (100), (101), (110), (011), and (114) surfaces of AgNbO<sub>3</sub>. Wulff construction was used to predict the available morphologies of this material and their transformations, which were matched with the experimental images obtained by electron microscopy to support our findings. Our data indicate that the undercoordinated O anions and Ag and Nb cations on these surfaces act as frustrated Lewis base and acid pairs, respectively, to control their structure and electronic properties. These sites at the (110) and (010) selectively bind H<sub>2</sub>O and O<sub>2</sub> molecules, opening an energetically favorable pathway for the dissociation of H<sub>2</sub>O to enhance the initial stages of the formation of reactive oxygen species, ⋅OH, ⋅O<sub>2</sub><sup>−</sup> and ⋅OOH radicals, which adsorbed strongly on both surfaces within a simplified model. Overall, the results demonstrate that careful consideration of the impacts of surface chemistry on the behavior of AgNbO<sub>3</sub> surfaces is required to further understand and tailor the reactivity based on the generation of these highly reactive species.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312611","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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Structural evolution, electronic and bonding properties of neutral and anionic magnesium clusters doped with two sodium atoms 掺杂两个钠原子的中性和阴离子镁团簇的结构演变、电子和成键特性

IF 3.1 3区材料科学

Computational Materials Science Pub Date : 2024-09-20 DOI: 10.1016/j.commatsci.2024.113389

{"title":"Structural evolution, electronic and bonding properties of neutral and anionic magnesium clusters doped with two sodium atoms","authors":"","doi":"10.1016/j.commatsci.2024.113389","DOIUrl":"10.1016/j.commatsci.2024.113389","url":null,"abstract":"<div><div>Using CALYPSO code and DFT calculation, the geometry, stability, electronic and bonding properties of bimetallic Na<sub>2</sub>Mg<em><sub>n</sub></em><sup>0/–</sup> (<em>n</em> = 1–11) are comprehensively studied. It is found that the structural transition from 2D to 3D occurs at <em>n =</em> 3 for neutral Na<sub>2</sub>Mg<em><sub>n</sub></em> and <em>n =</em> 2 for their anions. From <em>n =</em> 8, the dominant structures of Na<sub>2</sub>Mg<em><sub>n</sub></em><sup>0/–</sup> is transformed into a triangular prismatic hollow geometry. Most of them are structurally different from their individual Mg clusters. Sodium atoms tend to the peripheral region and act as electron donors in the Na<sub>2</sub>Mg<em><sub>n</sub></em><sup>0/–</sup> clusters. Analysis of stability suggests excellent stability of the Na<sub>2</sub>Mg<sub>3,9</sub> and Na<sub>2</sub>Mg<sub>3,8</sub><sup>–</sup> clusters, probably due to their compact magnesium structural units and full or quasi-full electronic shell configurations. Bonding character analysis reflects covalent bonds for Mg-Mg interaction and non-covalent bonds for Na-Mg interaction, resulting in stronger Mg-Mg bonds than Na-Mg bonds in the Na<sub>2</sub>Mg<sub>3,9</sub> and Na<sub>2</sub>Mg<sub>3,8</sub><sup>–</sup> clusters.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312612","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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A skeletonization-based approach for individual fiber separation in tomography images of biocomposites 在生物复合材料断层扫描图像中分离单个纤维的骨架化方法

IF 3.1 3区材料科学

Computational Materials Science Pub Date : 2024-09-20 DOI: 10.1016/j.commatsci.2024.113372

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Structural and magnetic properties of transition metal Co doped and III (B, Al, Ga) element co-doped Zn12Se12 clusters: A theoretical investigation 过渡金属 Co 掺杂和 III（B、Al、Ga）元素共掺杂 Zn12Se12 团簇的结构和磁特性：理论研究

IF 3.1 3区材料科学

Computational Materials Science Pub Date : 2024-09-20 DOI: 10.1016/j.commatsci.2024.113369

{"title":"Structural and magnetic properties of transition metal Co doped and III (B, Al, Ga) element co-doped Zn12Se12 clusters: A theoretical investigation","authors":"","doi":"10.1016/j.commatsci.2024.113369","DOIUrl":"10.1016/j.commatsci.2024.113369","url":null,"abstract":"<div><div>To explore stable magnetic semiconductor clusters, Zn<sub>12</sub>Se<sub>12</sub> was selected as the host material, Co doped and III (B, Al, Ga) element co-doped Zn<sub>12</sub>Se<sub>12</sub> clusters were investigated with first principle all-electron calculations. Geometry optimization, frequency calculations and dynamics simulations were performed to determine stable clusters. The analysis revealed that in Co doped Co<sub>2</sub>Zn<sub>10</sub>Se<sub>12</sub> clusters, two Co atoms preferentially substituted for adjacent Zn atoms in opposite vertices of a rhombus, resulting in the shortest Co-Co distance. The introduction of III (B, Al, Ga) elements generated the most stable Co<sub>2</sub>IIIZn<sub>9</sub>Se<sub>12</sub> cluster, where two Co atoms replaced adjacent Zn atom sites, and III atoms replaced the Zn atom site nearest to the Se atom between the two Co atoms. Energy differences between ferromagnetic and antiferromagnetic states indicated that the Co<sub>2</sub>Zn<sub>10</sub>Se<sub>12</sub> clusters exhibited an antiferromagnetic coupling state, whereas the Co<sub>2</sub>IIIZn<sub>9</sub>Se<sub>12</sub> clusters exhibited ferromagnetic coupling states. A detailed analysis of electron density and electronic configurations for Co element was conducted to uncover the magnetic coupling mechanism. It was found that the introduction of III elements as donor doping decreased the Co-Se hybridization, which reduced the antiferromagnetic superexchange coupling while forming the Se-Co-Se-III bonds with an excess electron, thereby enhancing the Co-Co ferromagnetic double-exchange coupling. The strategy of III element co-doping facilitated ferromagnetic double-exchange coupling between Co atoms, providing valuable insights for the exploration of new dilute magnetic semiconductor materials.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312697","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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Computational prediction of a new metallic silicon allotrope 新型金属硅同素异形体的计算预测

IF 3.1 3区材料科学

Computational Materials Science Pub Date : 2024-09-20 DOI: 10.1016/j.commatsci.2024.113380

{"title":"Computational prediction of a new metallic silicon allotrope","authors":"","doi":"10.1016/j.commatsci.2024.113380","DOIUrl":"10.1016/j.commatsci.2024.113380","url":null,"abstract":"<div><div>Silicon, a crucial element in modern technological advancements, significantly contributes to various sectors such as electronics and solar energy conversion systems. The need to investigate novel silicon materials with promising applications is on the rise, leading to the identification of various new silicon allotropes. By first-principles calculations, we identify a new silicon phase in <span><math><mrow><mi>R</mi><mover><mrow><mn>3</mn></mrow><mrow><mo>̄</mo></mrow></mover></mrow></math></span> (<span><math><msubsup><mrow><mi>C</mi></mrow><mrow><mn>3</mn><mi>i</mi></mrow><mrow><mn>2</mn></mrow></msubsup></math></span>) symmetry, which has a rhombohedral primitive cell with 7 silicon atoms, thus termed as R-Si7. The dynamic and thermal stabilities of R-Si7 have been verified by phonon mode analysis and <em>ab initio</em> molecular dynamics simulations, respectively. The mechanic properties of this new silicon allotrope has also been investigated. The X-ray diffraction patterns have been simulated and provided more structural information of R-Si7. Besides, the calculated electronic band structures and projected density of states show that R-Si7 is a metallic silicon material, and its conductivity mainly stems from the <span><math><mi>p</mi></math></span>-orbital electrons of silicon. These results pave the way for further exploration of this new silicon phase and its outstanding properties.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312695","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}

引用次数: 0

Grain boundary grooving in thin film under the influence of an external magnetic field: A phase-field study 外磁场影响下的薄膜晶界开槽：相场研究

IF 3.1 3区材料科学

Computational Materials Science Pub Date : 2024-09-19 DOI: 10.1016/j.commatsci.2024.113378

{"title":"Grain boundary grooving in thin film under the influence of an external magnetic field: A phase-field study","authors":"","doi":"10.1016/j.commatsci.2024.113378","DOIUrl":"10.1016/j.commatsci.2024.113378","url":null,"abstract":"<div><div>Using a phase-field model, we study the surface diffusion-controlled grooving of a moving grain boundary under the influence of an external magnetic field in thin films of a non-magnetic material. The driving force for the grain boundary motion comes from the anisotropic magnetic susceptibility of the material, leading to the free energy difference between differently oriented grains. We find that, above a critical magnetic field, the grain boundary motion is in a steady state, and under this condition, the mobile thermal groove exhibits a universal behavior — scaled surface profiles are time-invariant and independent of thermodynamic parameters. The simulated universal curve agrees well with Mullins’ theory of mobile grooves for any groove shape. We extend our study to a three-dimensional polycrystalline thin film with equal-sized hexagonal grains. We observe a preferential grain growth depending on the applied magnetic field direction, which can be leveraged for field-assisted texture control of polycrystalline thin films. Our study reveals that keeping other conditions the same, the rate of pitting at the vertices of the hexagonal grains substantially decreases in the presence of the external magnetic field.</div></div>","PeriodicalId":10650,"journal":{"name":"Computational Materials Science","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312636","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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