Release Time:2019-03-12  Hits:

Indexed by: Journal Article

Date of Publication: 2017-02-01

Journal: JOURNAL OF NUCLEAR MATERIALS

Included Journals: EI、SCIE

Volume: 484

Page Number: 276-282

ISSN: 0022-3115

Key Words: H retention; Diffusion; Vanadium alloys; First principles

Abstract: 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.