Diffusion of particles, adsorbed on a reconstructive surface

The influence of surface reconstruction on diffusion of adsorbed particles is investigated in the framework of simple two-position symmetrical model. Exact expressions for the free energy and diffusion coefficient are obtained neglecting the lateral interaction between the adsorbed particles. The critical behavior of the system is described by an anisotropic Ising spin model. The coverage dependencies of the chemical diffusion coefficient are calculated for different temperatures and interaction parameters. The dependencies show clearly the strong influence of the phase transitions, occurring in the system, on the particle migration. The chemical diffusion coefficient turns to zero at the critical points of the system.