Adsorption model of non-additive binary gas mixture on square lattice: attraction between molecules of different types

Abstract

Adsorption of binary gas mixtures on the lattice of solid is of considerable interest both from the practical and the theoretical
points of view. The simplest theoretical model taking into account the lateral interactions between adsorbed molecules is a lattice gas model with nearest-neighbor interactions. We have done complete analysis of the ground-state phase diagram for this model on a square lattice taking into account nearest-neighbor attraction between molecules of different types and arbitrary interactions between one type molecules. Regions of phase stability are determined using the principle of grand potential minimum. As a result we have constructed a partition of the model parameter plane into 14 regions differing by the type of the phase diagrams.