A DIFFUSION MODEL IN NANOCRYSTALLINE MATERIALS
纳米微晶材料的扩散机制

The activation energies,the preexponential factors and the corresponding self-diffusion coefficients for a nanocrystalline material in various diffusion conditions were calculated. Based on comparison of the calculated self-diffusions with the experimentally measured one, it is suggested that the diffusion model in nanocrystals is a complex one with the combination of the boundary diffusion by the vacancy mechanism and the internal surface diffusion of atoms along internal surfaces of boundary voids.