The diffusivity of H and D was measured at temperatures of between 773 and 1373K (figure 7), by using gas absorption methods and H and D atomic ratios of less than 0.0001. It was found that the diffusion coefficients for H and D exhibited Arrhenius behavior. The dependence of the D/H diffusivity ratio upon temperature was explained in terms of a model for diffusion in which a H atom in an octahedral site of the Pd lattice could jump into an adjacent octahedral site only when local deformation of the Pd lattice assisted the jump.

T.Maeda, S.Naito, M.Yamamoto, M.Mabuchi, T.Hashino: Journal of the Chemical Society - Faraday Transactions, 1994, 90[6], 899-903