Role of surface diffusion in the ordering of adsorbed molecules: dynamic Monte Carlo simulations of NO on Rh(111)

The saturation coverage of molecules adsorbed on metal surfaces is often se en to increase with temperature of adsorption, and may be accompanied by th e ordering of the molecules into periodic structures at higher temperatures . The case of NO on Rh(111) presents a specific example of this behavior. M odelling the adsorption process by means of Monte Carlo simulations in whic h diffusion and lateral interaction are considered indicates that both the increase of the saturation coverage and the ordering with increasing adsorp tion temperature are in agreement with an enhanced mobility of the adsorbed molecules. (C) 1999 Elsevier Science B.V. All rights reserved.