MOLECULAR-DYNAMICS STUDY OF THE DIFFUSION OF HYDROGEN IN SOLID PALLADIUM

The diffusion of hydrogen atoms in solid palladium is studied via a mo lecular dynamics simulation. In this calculation, the palladium atoms are fixed on the sites of the fcc lattice and the hydrogen atoms are i nitially put on the O (octahedral) sites. Through the present molecula r dynamics simulation, the diffusion constant and activation energy ar e calculated for several different concentrations of hydrogen atoms. W e find that the hydrogen atoms show jump motions between the O sites w hich lead to super diffusion in the solid palladium. We have also obta ined the temperature dependence and concentration dependence of the va cancy factor and jump correlation functions.