Characteristics of Helium Diffusion Trajectory: A Molecular Dynamics Study

Molecular dynamics (MD) are employed to explore the features of Helium atom and He clusters diffusion in titanium at the temperatures between room temperature and 667k. The results demonstrate that the frequency for Helium atom jumping from site to site increases with the increasing temperature. Another important feature is that the diffusion of a He atom and a He trimer is a layered structure. The difference is that the trajectory of a He atom is between two Ti atom layers of (001) planes, and the trajectory of a He trimer is overlapped with the Ti atom layers of (001) plane. Meanwhile, it is observed that the layered structured diffusion becomes ambiguous for a He atom and a He trimer when the temperature is increased. The conclusion emphasizes different migration features for He clusters of various sizes.