Indexed on: 07 May '13Published on: 07 May '13Published in: Science China Physics, Mechanics & Astronomy
We investigate the structure, trapping, and diffusion behaviors of helium (He) at vacancy in a Fe single crystal using first-principles simulations. Vacancy with more space can provide the lower electron density region for He binding in comparison with intrinsic Fe, causing He to diffuse into the vacancy inner easily. We provide the quantitative microscopic studies related to the atomic-level thermo-kinetic trapping processes. Moreover, such physical viewpoint can be applied to other vacancy-like defects such as vacancy clusters, void and grain boundaries which can open a space with reduced electron density region to increase He binding in metals and metal alloys.