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Indexed by:期刊论文

Date of Publication:2017-02-15

Journal:13th International Conference on Computer Simulation of Radiation Effects in Solids (COSIRES)

Included Journals:SCIE、EI、CPCI-S

Volume:393

Page Number:130-134

ISSN No.:0168-583X

Key Words:Helium; Diffusion; Vanadium alloys; First principles

Abstract:The effect of Ti/Cr additive on He diffusion and segregation properties in dilute vanadium alloys is investigated using first-principles calculations. First we determined the He preference site and investigated the He-Cr/He-Ti interactions. Energetically, He prefers to segregate to Ti regions rather than Cr regions. The most stable site for interstitial He is a tetrahedral site near Ti. He-Ti interactions have a weak attraction while He-Cr interactions have a weak repulsion. Kinetically, He diffusion to Ti has a lower energy barrier; contrarily the He barrier increases towards Cr. Furthermore, we discuss the stability of He-n-Cr/Ti complexes and He-n-vacancy-Cr and Ti complexes with n = 1-8. It is found that the HenTi complexes are more stable than the HenCr complexes while the Hen-vacancy-Ti complexes are less favorable than He-n-vacancy-Cr. The findings give a reference for understanding the mechanism of He embrittlement under irradiation. (C) 2016 Elsevier B.V. All rights reserved.