Kinetic Monte Carlo investigation of Xe adsorption and desorption on Pt(111) and Pt(997)

Abstract

A discrete event kinetic Monte Carlo (KMC) simulation is applied to model the desorption behavior of Xe on Pt(111) and to study the adsorption and desorption behavior of Xe on the vicinal Pt(997) surface. The simulation results are compared to recent experimental data. For Xe/Pt(111) a phase transition occurs during the desorption, which leads to a change in the desorption behavior from first order for low initial Xe coverage to zero order at higher coverage. The KMC simulation is able to reproduce this transition and hence the experimental desorption spectra by assuming a strongly reduced effective pairwise interaction between neighboring Xe atoms. The vicinal Pt(997) surface presents a nanostructured template substrate, which is well suited to study the influence of step edges and narrow terraces on the adsorption and desorption properties of Xe. Different interaction models were tested by KMC simulations on their ability to reproduce the experimentally observed growth and desorption behavior.