Dynamics of confined Xe monolayers adsorbed on the Pt(997) vicinal surface

The dynamics of a confined discrete xenon monolayer adsorbed on the vicinal Pt(997) surface is analyzed within a semi-empirical potential approach. We have investigated two monolayer geometries, namely the commensurate phase and the quasi-hexagonal incommensurate phase, which seem to be stable on the (111) face of Pt, depending on the terrace size. We show that the number and the behavior of localized and side modes characteristic of the confinement are completely different in the two phases. Inelastic helium scattering experiments with a resolution better than 0.2 meV should be an efficient tool to detect the localized modes of the monolayer. This could be an additional way to elucidate the structure of Xe/Pt(997), which has not yet been well established.