COMPUTER-SIMULATION STUDIES OF ADSORPTION OF SIMPLE GASES ON ALKALI-METAL SURFACES

Wetting properties of simple gases on alkali metal surfaces are of fun damental importance because they manifest the least attractive gas-sur face interactions in nature and because their critical behavior is des cribed by the two-dimensional Ising model. We report simulation result s for the adsorption of neon and hydrogen on alkali metal surfaces. Th ese use the grand canonical (classical) Monte Carlo and (quantum) path integral Monte Carlo methods, respectively. We find a set of wetting transitions at temperatures which are very sensitive to the adsorption potentials. Comparison is made with recent experiments and with predi ctions of a model of Cheng, et al. in which the transition temperature is estimated from a simple cost-benefit analysis involving the surfac e tension and the adsorption potential.