The H chemical diffusion coefficient was deduced from the kinetics of the gas/solid-surface reaction at 350 to 1000K. The H mobility was also investigated by means of mechanical spectroscopy at 240 to 260K, where a Snoek internal friction peak occurred at frequencies in the kHz range. Data on the Einstein diffusion coefficient, obtained from the relaxation time of the Snoek effect, were correlated with the high-temperature absorption results. The combined data could be described by:

D (cm2/s) = 2 x 10-3 exp[-0.47(eV)/kT]

A.Biscarini, B.Coluzzi, G.Mazzolai, F.M.Mazzolai: Journal of Alloys and Compounds, 2005, 404-406, 261-4