Ab Initio Study Of The Behavior Of Helium In Different Erbium Hydrides

First-principle is used to study the migration and occupancy of He in different phases (a phase (ErH<1.8), beta phase (ErH2), gamma phase(ErH3)) of Erbium hydride. The migration energy evolution is obtained by the NEB method. Calculation shows that the migration energy of He in three phases are affected not only by migration path but also by the hydrogen storage ratio. According to the calculation, the migration energy of beta phase and gamma phase is higher than a phase. This means He bubbles is easier to accumulate in a phase than in beta phase and gamma phase. While H vacancies exist, the migration energy of beta phase and gamma phase is always lower than that without H vacancy.