The diffusive behavior of Cu in 4N5-purity single crystals was studied at 387 to 600C. The results could be described by:

D (cm2/s) = 6.0 x 10-2 exp[-28.6(kcal/mol)/RT]

M.Beyeler, F.Maurice, R.Seguin: Mémoires Scientifiques de la Revue de Métallurgie, 1970, 67, 295-302