Evidence for the roughening and wetting transitions in the lattice-gas model of adsorption from Monte Carlo simulations

Abstract

The formation of a dense adsorbed film on a smooth substrate is studied via Monte Carlo simulations of a lattice gas with nearest-neighbor interactions. The existence of the wetting transition which is predicted by a simple meanfield approximation is verified. We also find the sequence of first-order transitions which appear in the mean-field approximation. In contrast to the predictions of the mean-field approximation, the critical temperatures of these transitions appear to approach a limiting value well below the critical temperature of the bulk three-dimensional lattice gas as the thickness of the adsorbed film increases. This behavior, which was first predicted on physical grounds by de Oliveira and Griffiths, is presumably closely related to the roughening transition of the interface between the dense and tenuous bulk phases.