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论文类型： 期刊论文

发表时间： 2017-02-01

发表刊物： JOURNAL OF NUCLEAR MATERIALS

收录刊物： SCIE、EI

卷号： 484

页面范围： 276-282

ISSN号： 0022-3115

关键字： H retention; Diffusion; Vanadium alloys; First principles

摘要： We systemically investigated diffusion and retention of hydrogen (H) in vanadium (V) in presence of Ti/ Cr and determined the stability of H-n clusters and H-n-vacancy clusters (n = 1-6) near Cr/Ti using first principles calculations. H prefers a tetrahedral site near Ti than other interstitial sites. H-Cr interactions have a weak repulsion contrarily H-Ti interactions have a weak attraction. Kinetically, H diffusion barrier decreases towards Ti, while it increases towards Cr. Ti and Cr block H mobility in V alloys. Moreover, HnTi clusters are quite stable while HnCr clusters are less stable. Ti enhances H retention by acting as a trapping site for multiple H atoms in similar with vacancy, and a Ti atom can trap at least six H atoms. The stability of H-vacancy-Cr/Ti complexes and vacancy-Cr/Ti trapping for multiple H atoms are discussed. The findings are valuable for understanding the mechanism of H bubble nucleation and H embrittlement under irradiation. (C) 2016 Elsevier B.V. All rights reserved.