Polarization energy in the atom-surface interaction from optical data

Abstract

Calculations of the coefficient C 3 of the polarization energy in the atom-surface interaction are performed for several atom-substrate pairs using experimental data for the optical constants of the atom and the substrate. Results are in good agreement with values derived from selective adsorption molecular beam experiments. It is found that for the range of separations probed in a beam deflection experiment with Cs on Au there are appreciable retardation effects. The results of calculations for Xe and for Kr on basal plane graphite, including the effect of anisotropy in the graphite dielectric function, compare poorly with information obtained from multilayer adsorption isotherms. An extension of the theory of the polarization energy is presented: the non-retarded interaction is evaluated for an anisotropic substrate, using a Drude model.