The diffusivity and migration energy of H at high temperatures were found to be consistent with low-temperature data when the possibility of temporary localization of the H atoms at thermal equilibrium vacancies was taken into account:

D(m2/s) = 8 x 10-5exp[-0.52(eV)/kT]

From these data, the H-vacancy binding energy was estimated to be equal to 0.43eV.

S.Linderoth: Philosophical Magazine Letters, 1988, 57[4], 229-34