STRUCTURE AND DYNAMICS OF ADSORBED FILMS. EFFECTS OF DIMENSIONALITY AND SUBSTRATE POTENTIAL

Abstract

Molecular dynamics simulations of argon films on the (001) surface of graphite are reported and compared with experimental data. Three different levels of approximation have been investigated : three-dimensional systems interacting with a smooth substrate, and twodimensional ones both with and without lateral periodic substrate potentials. In particular, a broad melting transition at about T = 45 K is identified and characterized. Effects of second layer promotion are also investigated. The substantial agreement of all three calculations with each other and with experiments on submonolayer films suggests that the observed phenomena in this regime are characteristic of two-dimensional systems