The electrochemical diffusion of H through α-Pd was considered. During permeation, variations in the electrode potential and current density at the cathode surface were found to correspond to those in the dissolved H content and the H entry flux at the cathode surface, respectively. The diffusivity of H at 278 to 333K was determined by using potentiostatic step-charging and step-stripping methods, and could be described by:

D (cm2/s) = 2.40 x 10-3 exp[-5.1(kcal/mol)/RT]

H.Hagi: Materials Transactions, 1990, 31[10], 842-7