The diffusivities of H and D, at between 110 and 165K, could be described by:

H:   D (cm2/s) = 1.1 x 10-4 exp[-0.350(eV)/kT]

D:   D (cm2/s) = 8.8 x 10-4 exp[-0.395(eV)/kT]

Low-Temperature Isotope Effect of Hydrogen Diffusion in FCC Metals and Alloys. B.Hohler, H.Kronmüller, H.: Philosophical Magazine A, 1981, 43[5], 1189-204