Investigations were made, by means of Monte Carlo simulations, of the diffusion of adsorbates on a square lattice. The lattice contains inaccessible sites forming linear barriers. The adsorbate atoms did not interact among themselves, except for the hard core. The tracer diffusion coefficients, reduced by their values in the absence of the barrier, were plotted versus the length of the barrier. It was found that the diffusion along the barrier was not affected by its presence, whereas that perpendicular to it decreased linearly, for a large interval of the barrier, with its length. The reduced diffusion coefficient did not depend on the concentration of the diffusing particles, but its value increased with the perpendicular distance between the barriers.

Surface Tracer Diffusion in the Presence of a Solid Barrier: a Monte Carlo Study. A.Pȩkalski, M.Ausloos: Surface Science, 1995, 344[3], L1271-4