DISSOCIATIVE DIFFUSION OF FE-57 IN BETA-SN AS OBSERVED BY MOSSBAUER-EFFECT

The Mössbauer effect of Fe57 atoms in β-Sn was measured over the temperature range 90-462°K with a polycrystalline source specimen. The spectra were decomposed into two major pairs of doublet lines and a minor line. The results were interpreted in terms of a dissociative diffusion mechanism. The lines were assigned to interstitial, substitutional, and clustered Fe57 atoms. The diffusional broadening gave the diffusion coefficient of interstitial Fe atoms along the c axis as Di=1.8(±0.6)×10-4exp[-0.47(±0.07)kT]. The effective solute diffusivity comparable with a tracer diffusion coefficient turned out to be DI=4.8(±3.4)×10-4exp[-0.53(±0.08)kT]. © 1978 The American Physical Society.