Diffusion of particles over anisotropic heterogeneous lattices

The diffusion of particles adsorbed on an anisotropic heterogeneous surface with two non-equivalent sites arranged in the alternated rows is investigated in the framework of the lattice-gas model. Analysis of the particle migration reveals rather interesting non-trivial peculiarities of this process. The particle diffusion has a qualitatively different character depending on the direction of migration and particle concentration. Using an approach describing the migration by sequences of strongly correlated particle jumps we derived the analytical expressions for the diffusion coefficients. The calculated coverage dependencies of the jump and chemical diffusion coefficients have been compared with the numerical data obtained by kinetic Monte Carlo simulations. Very good coincidence between the data obtained by two independent methods corroborates strongly the correctness of the approach for description of the particle diffusion in such heterogeneous lattices.