The diffusivity was studied at 950 to 1250C by using neutron activation analysis and electrical measurements. The Ir diffused uniformly into the bulk, except for a near-surface layer (0.09mm) where its concentration decreased sharply. With increasing diffusion time, the increase in saturation level was related to a complex dissociative diffusion mechanism. The results could be described by:

D (cm2/s) = 4.2 x 10-2 exp[-1.3(eV)/kT]

S.A.Azimov, B.V.Umarov, M.S.Yunusov: Fizika i Tekhnika Poluprovodnikov, 1976, 10[7], 1418-9