Comparison of Monte Carlo simulations and macroscopic theories of diffusion in systems with non-ideal sources and sinks for vacancies

A new concept of generation and annihilation of vacancies at non-ideal dense sources and sinks for vacancies is incorporated into the standard Monte Carlo model for vacancy-mediated diffusion. This model enables to treat the vacancy wind as well as the deformation of the specimen and the shift of the Kirkendall plane. The Monte Carlo model is used for testing the recent macroscopic theories of diffusion by Darken [Trans. Am. Inst. Min. Eng. 175 184 (1948)], Manning [Phys. Rev. B 4 1111 (1971)] and Moleko et al. [Phil. Mag. A 59 141 (1989)]. The agreement with the self-consistent Moleko et al. theory is excellent. On the other hand, the agreement with the classical Darken theory frequently used in the open literature for the explanation of the Kirkendall effect is rather poor.