The structure of the clean Mo[001] surface

Abstract

An analysis of low-energy-electron-diffraction data from a clean Mo{001} surface was carried out, which has determined the atomic structure of this surface and provided the parameters of a scattering model needed to analyze ordered overlayers. The analysis was based upon the comparison between the intensity spectra calculated with the layer-Korringa-Kohn-Rostoker method and the spectra determined experimentally for six nondegenerate diffracted beams at 8° and four nondegenerate diffracted beams at 21° incidence of the primary electron beam. Satisfactory fit to experimental spectra was obtained with a model using an energy-dependent inner potential varying from 16 to 13 eV, an imaginary potential of 4 eV, bulk and surface Debye temperatures of 360 and 150 °K, and a first underlayer spacing of 1.39 ÅA; thus the Mo{001} surface is contracted by 11.5% with respect to bulk {001} planes. The sensitivity of the calculated spectra to changes in a number of structural and nonstructural model parameters is demonstrated and discussed.