Variable Energy Experiments on Atomic Beam Scattering from a NaF (001) Surface

Abstract

Velocity selected hydrogen and deuterium atoms with kinetic energies from 20 meV to 140 meV have been scattered and diffracted from a NaF (001) cleavage plane. Highly resolved minima of selective adsorption yield binding energies and the gas-atom-surface interaction potential perpendicular to the surface. Specular intensity versus incident energy curves and specular intensity versus angle of incidence curves for different surface temperatures are compared to available theories. From these measurements the Debye-Waller-factor is extracted, which depends on the angle of atomic incidence and is characterised by a surface Debye temperature of θD⊥=370 K and the depth of the attractive potential D0=17.9 meV. The strength of the (first order) periodic part of the potential is found to be D1=0.025 D0.