The surface of a single crystal was coated with 131I radio-tracer, and diffusion annealing was carried out at temperatures of between 170 and 232C. The concentration profiles were then determined by sectioning. It was found that the diffusivity results (table 191) could be described by the expression:

D (cm2/s) = 9.9 x 10-2 exp[-0.98(eV)/kT]

V.G.Goffman, A.A.Skujina, Y.E.Tiliks, E.A.Ukshe: Elektrokhimiya, 1981, 17[8], 1261-3