The diffusive behavior of Cu in 5N-purity single crystals was studied at 775 to 1050C. The results could be described by:

D (cm2/s) = 2.7 x 10-1 exp[-61.02(kcal/mol)/RT]

H.Helfmeier, M.Feller-Kniepmeier: Journal of Applied Physics, 1970, 41[8], 3202-5