He atom scattering from ZnO surfaces: Calculation of diffraction peak intensities using the close-coupling approach

Abstract

Diffraction intensities of a molecular He beam scattered off the clean and water-covered ZnO(10 1̄0) surface have been simulated using a new potential model in conjunction with the close-coupling formalism. The effective corrugation functions for the systems He-ZnO(10 l̄0) and He-H 2O/ZnO(10 1̄0) have been obtained from density functional theory calculations within the Esbjerg-Nørskov approximation. Using these data a potential model is constructed consisting of a corrugated Morse potential at small He-surface distances and a semiempiric attractive part at larger distances. The diffraction patterns obtained from close-coupling calculations agree with the experimental data within about 10%, which opens the possibility to simulate He diffraction from surfaces of any structural complexity and to verify surface and adsorbate structures proposed theoretically by employing this kind of analysis. © 2010 IOP Publishing Ltd.