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

(110):     D (cm2/s) = 4.4 x 10-2 exp[-17.9(kcal/mol)/RT]

(211):     D (cm2/s) = 9.0 x 10-8 exp[-11.2(kcal/mol)/RT]

(321):     D (cm2/s) = 1.9 x 10-5 exp[-15.4(kcal/mol)/RT]

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