The bulk diffusion coefficients were measured by means of secondary-ion mass spectrometry of Ir single crystals that had been annealed in a so-called technical oil-less vacuum at 1300 to 2000K. The Arrhenius plot could be described by:

D (m2/s) = 1.7 x 10-10exp[-193(kJ/mol)/RT]

The binding energy of the components of the vacancy-impurity complexes was determined to be 116kJ/mol.

A.V.Ermakov, S.M.Klotsman, S.A.Matveev, G.N.Tatarinova, A.N.Timofeev, V.K.Rudenko, N.I.Timofeev, G.F.Kuzmenko: Physics of Metals and Metallography, 2002, 93[5], 435-42