Electrochemical permeation experiments were performed on annealed samples (Pd-electroplated 0.7mm membranes) of 2N8-purity a-phase material in 0.1N NaOH electrolyte at temperatures of between 290 and 350K. It was found that the results could be described by the expression,

D (m2/s) = 5.12 x 10-8 exp[-4.32(kJ/mol)/RT]

The binding energy in the membranes was estimated to be 21.4kJ/mol, and was attributed to dislocation or grain boundary interactions with the permeating H.

K.Yang, A.P.Xian, M.Z.Cau, X.J.Wan: Scripta Metallurgica, 1988, 22[3], 355-7