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

The best linear fits to the solute diffusion data ([5] to [25]) yield:

H (sd): Ln[Do] = 1.49E – 21 (R2 = 0.87); W(sd): Ln[Do] = 0.33E – 16.1 (R2 = 0.63)