Atomic and Molecular Scattering from Surfaces Elastic Scattering

Abstract

The scattering of neutral thermal atoms and molecules (typical data: temperature 300K; kinetic energy 50 meV, De Broglie wave length 1 Å) from solid surfaces has born out in the last 15 years many interesting and detailed results. With regard to physical (not chemical) interaction of atoms with surfaces elastic scattering events are possible among them most strikingly diffraction. An important special diffraction process is the resonant transition of atoms to bound states at the solid surface. The analysis of elastic events yields information on the gasatom-crystal surface interaction potential, on the surface topology (i.e. lattice constant and steps), on the thermal mean square displacement of surface atoms, on surface phonons and surface impurity.

This paper presents some theoretical background, introduces to experimental methods and discusses selected and very recent results as examples for the efforts towards a better understanding of gasatom-solid surface interaction, which is important in fundamental research as well as in aerodynamics, corrosion and heterogeneous catalysis.