DYNAMIC OF SURFACE DIFFUSION PROCESS WITH PRESENCE OF ORDERING

Abstract

A Monte Carlo simulation of the dynamics of diffusion process is presented in the framework of the lattice gas model. The considered lattice is of square geometry with lateral interaction energy between diffusive adsorbates. The paper is entirely devoted to first J FN and second J SN neighboring repulsive interactions with the ratio R=J SN /J FN in the [0, 1] interval. It is shown that repulsive second neighboring interaction allows emergency of new ordered phases at the coverages theta = 1/4 and 3/4 and induces anisotropy when R is greater than the magnitude 0.5. The present situation is similar to that of Sadiq and Binder, Surf. Sci.128, 350 (1985) except for the choice of transition probability. Particular attention is given to both the behavior of the tracer diffusion coefficient and to the static of the half-full lattice for which a complete phase diagram is derived from calculation of the apparent activation energy. Our dynamic calculations suggest that in the temperature range examined, the jump algorithm gives rise to acceptable results, even its criticable normalization factor.