Stability of vacancy-type defect clusters in Ni based on first-principles and molecular dynamics simulations

SCRIPTA MATERIALIA

卷:145

Article

Zhao, Shijun¹  Zhang, Yanwen^1,2  Weber, William J.^1,2 

[1] Oak Ridge Natl Lab, Mat Sci & Technol Div, Oak Ridge, IN 37831 USA

[2] Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA

关键词: Vacancy clusters;    Stacking fault tetrahedra;    First-principles calculations;    Ab initio molecular dynamics;   

DOI  :  10.1016/j.scriptamat.2017.10.003

来源: Elsevier

【 摘 要 】

Using first-principles calculations based on density-functional theory, the energetics of different vacancy-type defects, including voids, stacking fault tetrahedra (SFT) and vacancy loops, in Ni are investigated, It is found that voids are more stable than SET at 0 K, which is also the case after taking into account the volumetric strains. By carrying out ab initio molecular dynamics simulations at temperatures up to 1000 K, direct transformations from vacancy loops and voids into SFT are observed. Our results suggest the importance of temperature effects in determining thermodynamic stability of vacancy dusters in face-centered cubic metals. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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