The diffusive behavior of W on various W surfaces was studied. The results could be described by:

(110):     D (cm2/s) = 2.1 x 10-3 exp[-19.9(kcal/mol)/RT]

(211):     D (cm2/s) = 3.8 x 10-7 exp[-13.0(kcal/mol)/RT]

(321):     D (cm2/s) = 1.2 x 10-3 exp[-19.4(kcal/mol)/RT]

D.W.Bassett, M.J.Parsley: Journal of Physics D, 1970, 3[5], 707-16