Prewetting Transitions for a Model Argon on Solid Carbon Dioxide System

Grand canonical transition matrix Monte Carlo simulations are used to investigate the phase behavior of the model argon on solid carbon dioxide system introduced by Ebner and Saam (Phys. Rev. Lett. 1977, 38, 1486). Our results indicate that the system exhibits first-order prewetting transitions at temperatures above a wetting temperature of Tw = 0.598(5) and below a critical prewetting temperature of Tpwc approximately 0.92. The wetting transition is identified by determining the temperature at which the difference between the bulk vapor-liquid and prewetting saturation chemical potentials goes to zero. Coexistence is directly located at a given temperature by obtaining a density probability distribution from simulation data and utilizing histogram reweighting to determine the conditions that satisfy phase coexistence. Structural properties of the adsorbed films are also examined.