Diffusion of adsorbed particles with attractive lateral interactions at low temperature

Lateral interactions between particles in an adsorbed overlayer result in their 2D ordering and/or aggregation and also influence other various heterogeneous rate processes. The effect of lateral interactions on diffusion of adsorbed particles has been studied in detail in the situations when the temperature is above the critical one. Here, the author presents Monte Carlo simulations of adsorbate diffusion and aggregation at temperature appreciably below the critical one. Diffusion is considered to occur on a strip of sites under conditions when the coverage is maintained high on one of its sides and kept low on the other side. The corresponding patterns are shown to depend strongly on the ratio of lateral interactions in the ground state (near the bottom of potential wells) and in the activated state (at the saddle points of the potential barriers) for diffusion jumps.