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论文类型： 期刊论文

发表时间： 2017-02-15

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

收录刊物： SCIE、EI、CPCI-S

卷号： 393

页面范围： 130-134

ISSN号： 0168-583X

关键字： Helium; Diffusion; Vanadium alloys; First principles

摘要： 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.