Hydrogen solubility and diffusivity at Σ3 grain boundary of PdCu.

ABSTRACT

First principles calculations have been performed to comparatively reveal hydrogen solubility and diffusivity at grain boundaries of BCC and FCC PdCu phases. It is found that the temperature-dependent hydrogen solubility at BCC Σ3 (112) GB of PdCu seems much higher than that in BCC PdCu bulk, while hydrogen solubility in FCC Σ3 (111) GB of PdCu is much lower than that in its corresponding FCC bulk. Calculations also reveal that grain boundary has an important effect on hydrogen diffusion of BCC and FCC PdCu, i.e., hydrogen diffusivities of BCC Σ3 (112) and FCC Σ3 (111) grain boundaries of PdCu seem much smaller and bigger than those of its corresponding bulks, respectively. The predicted results could deepen the comprehension of hydrogen solubility and diffusion of PdCu phases.