It was noted that the correlation between the pre-factor and the effective activation energy for self-diffusion in amorphous alloys and grain boundaries was quite different to that observed for self-diffusion and impurity diffusion in crystals. Because the pre-factor reflected the details of the jump process, this correlation could be regarded as being key information in validating diffusion mechanisms. It was shown that known models for diffusion in crystals (via vacancy or interstitial migration), and of H in amorphous alloys (via interstitial migration), were compatible with experimentally observed correlations. An analysis of various aspects of diffusion in amorphous alloys and grain boundaries, including the isotope effect and pressure-dependence, showed that the observed correlation was caused by the nature of the disordered structures of the systems.

Diffusion in Amorphous Alloys and Grain Boundaries - the Correlation between Do and Q. V.Naundorf, M.P.Macht, A.S.Bakai, N.Lazarev: Journal of Metastable and Nanocrystalline Materials, 2000, 8, 21-6