Diffusion mechanisms in intermetallic compounds

In this paper we review the present understanding of the mechanisms of atomic diffusion in intermetallic compounds. Although it is well known that diffusion in intermetallic compounds is mediated by vacancies, there have been a number of very important subsets to this general mechanism that have been identified theoretically and these apparently dominate the diffusion process at specific conditions of temperature and composition. These include the six jump cycle mechanism, the triple defect mechanism, the antistructural bridge mechanism etc. We confine our review to the commonly taken B2 and L12 structures. The synergistic partnership between computer simulation and analytical theory has been particularly effective in suggesting and analysing possible diffusion mechanisms in intermetallic compounds