Ab initio study of the stability of intrinsic and extrinsic Ag point defects in 3C-SiC

JOURNAL OF NUCLEAR MATERIALS

卷:510

Article

Chen, Nanjun¹  Peng, Qing¹  Jiao, Zhijie¹  van Rooyen, Isabella²  Skerjanc, William E.³  Gao, Fei¹ 

[1] Univ Michigan, Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA

[2] Idaho Natl Lab, Fuel Design & Dev Dept, Idaho Falls, ID 83415 USA

[3] Idaho Natl Lab, Reactor Phys Design & Anal Dept, Idaho Falls, ID 83415 USA

关键词: Fission product;    Silicon carbide;    Point defects;    Density functional theory;   

DOI  :  10.1016/j.jnucmat.2018.08.053

来源: Elsevier

【 摘 要 】

We have systematically investigated the energetics and stability of Ag atom in 3C-SiC with various charge states using first-principles calculations within large supercells. Up to 18 Ag-defect configurations have been examined, including substitutionals, interstitials, and vacancy-based complexes. A general trend is that the formation energy of Ag-defect complexes is generally lower than interstitial typed defects. With the lowest formation energy, the configuration with Ag_T-Si-V-C(3+) turns out to be the most stable one. It has also been found a neutral Ag is more likely to substitute a silicon lattice site with a nearest carbon vacancy, thus forming an AgSiVC pair. All these data are important inputs in the next coarser-level modeling to understand the Ag migration in and release from 3C-SiC under both thermal and radiation conditions. (C) 2018 Elsevier B.V. All rights reserved.

【 授权许可】

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