Self-diffusion in metals

A calculation of the vacancy migration energy $E_v^m$ in normal metals is presented based on a new model of diffusion proposed by Kornblit et al. It is shown that normal self-diffusion in bcc metals, as opposed to fcc metals, is performed by a complex two-step mechanism. With respect to this mechanism, self-diffusion of alkali metals appears to be essentially different from diffusion in other bcc metals. The calculated migration energies for vacancy diffusion in bcc metals agree very well with available experimental data.