A theoretical and experimental study was made of the dependence of the ratio of the intensities, of the radiation components of 57Co, in the diffusion zones of polycrystalline samples. The ratio was shown to be sensitive to the type of coordination of atomic probes in the diffusion zone. An increase in the ratio, with depth in the diffusion zone, indicated a Gaussian profile. The latter was found during 1-dimensional bulk diffusion and during intercrystalline diffusion in the C-kinetics regime of bicrystals. A decrease in the ratio with penetration into the diffusion zone, especially for intercrystalline diffusion in polycrystals, was caused by the fact that the crystallite conjugation regions in such crystals were characterized by scatter of the diffusion coefficients in the crystallite conjugation region core. These were described by a distribution function rather than by a single value that was common to the whole sample. The existence of several independent diffusion fluxes led to the appearance of several extrema in the ratio-versus-y dependence.

Studying the Properties of a New Parameter Sensitive to the Type of Coordinate Dependence of the Concentration of Atomic Probes in the Diffusion Zone. S.M.Klotsman, N.Timofeev, M.I.Kurkin, V.V.Dyakin: Physics of Metals and Metallography, 1998, 86[2], 173-8