Dissolution, diffusion and permeation behavior of hydrogen in vanadium: a first-principles investigation

作者:Luo, Jian*; Zhou, Hong-Bo; Liu, Yue-Lin; Gui, Li-Jiang; Jin, Shuo; Zhang, Ying; Lu, Guang-Hong
来源:Journal of Physics: Condensed Matter , 2011, 23(13): 135501.
DOI:10.1088/0953-8984/23/13/135501

摘要

Employing a first-principles method, we have studied the stability, diffusivity, and permeation properties of hydrogen (H) and its isotopes in bcc vanadium (V). A single H atom is found to favor the tetrahedral interstitial site (TIS) in V. The charge density distribution exhibits a strong interaction between H and its neighbor V atoms. Analysis of DOS and Bader charge reveals that the occupation number of H-induced low energy states is directly associated with the stability of H in V. Further, H is shown to diffuse between the neighboring TISs with a diffusion barrier of 0.07 eV. Diffusion coefficients and permeabilities of H isotopes in V are estimated with empirical theory. At a typical temperature of 800 K, the diffusion coefficient and the permeability of H are 2.48 x 10(-4) cm(2) s(-1) and 2.19 x 10(-9) mol m(-1) s(-1) Pa-1/2, respectively.