Diffusion of protium and deuterium in α- and β-phases of LaNi5

Diffusion process parameters for low (alpha-phase) and considerable concentrations of implanted hydrogen atoms (beta phase) into LaNi5 have been studied. LaNi5 hydridation kinetics with two hydrogen isotopes (H2 and D2) was investigated by a volumenometric method at 208-303 K and 0.8-16 kPa. Temperature dependences of protiUm and deuterium diffusion coefficients in alpha- and beta-phases of LaNi5 have been obtained. A genera lized kinetic equation for determining diffusion coefficients in the beta-phase and a reaction on alpha- and beta-phase interface has been derived. It is shown that the Arrhenius equation parameters describing the diffusion change depending on the degree of interstitial filling which is related to the different type interstitial redistribution of hydrogen atoms. Data on the isotopic diffusion effect doesn't contradict the mechanism suggested