Anomalies in inelastic collision of methane molecular beam scattered from a Pt(111) surface

Abstract

Molecular beam scattering from a Pt(111) surface has been performed using methane molecules with a kinetic energy ranging from 190 to 570 meV, and the results obtained are compared with the classical Hard cube model (HCM). Good qualitative agreement is obtained as far as the dependence of the angular distribution of reflected molecules on both surface temperature and beam energy is concerned. Anomalous behavior of experimental data is understood in terms of the modification of the surface by adsorption of methane intermediate methyl fragments or more likely ethylidyne found by collision-induced dissociation of methane molecules. He atom scattering (HAS) analysis is applied to monitor the corrugation in a potential energy surface which is modified by adsorption of foreign species.