INFLUENCE OF STEPS ON ATOMIC ADSORPTION AND SEQUENTIAL GROWTH ABOVE VICINAL SURFACES

Abstract

Two different situations corresponding to out-of-equilibrium growth of an adsorbate and to equilibrium adsorption of a gas are discussed using the vicinal face of a transition metal as the substrate. Monte-Carlo simulations in the kinetic and equilibrium regimes are applied to the ordering of Xe and Ag atoms close to the monatomic steps of the (997) vicinal face of platinum. It is shown that the steps can favor the growth of one or two rows of adatoms (row-by-row growth) in the submonolayer domain, depending on the temperature and on intrinsic parameters connected to the magnitude of the interactions between the adspecies themselves and between these adspecies and the substrate. Such a behavior is consistent with very recent helium atom scattering experiments.