Permeation and mass spectroscopy techniques were used to determine H diffusion coefficients in 3N-purity single crystals and polycrystals. It was found that the diffusion coefficients were independent of the H concentration. Overall, the results for temperatures of 400 to 1200C could be described by:

D (cm2/s) = 6 exp[-24.7(kcal/mol)/RT]

A.P.Kakharov, V.M.Sharapov, E.I.Evko: Fiziko-Khimicheskaya Mekhanika Materialov, 1973, 9[2], 29-33