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

(110):     D (cm2/s) = 8.9 x 10-5 exp[-18.0(kcal/mol)/RT]

(211):     D (cm2/s) = 2.7 x 10-5 exp[-13.4(kcal/mol)/RT]

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