The specific features of diffusion in nanocrystalline material were considered. Theoretical models were suggested which described the effects of transformations (climb, splitting) of grain-boundary dislocations and disclinations upon self-diffusion in nanocrystalline materials. It was shown that the climb of grain-boundary dislocations strongly enhanced diffusion in nanocrystalline materials; thus causing the self-diffusion coefficient to be increased by several orders of magnitude.

Effects of Transformations of Grain Boundary Defects on Diffusion in Nanocrystalline Materials. I.A.Ovidko, A.B.Reizis, R.A.Masumura: Material Physics and Mechanics, 2000, 1[2], 103-10