Surface barrier for electrons in metals

Density-functional calculations using the full-potential linearized augmented-plane-wave (FLAPW) film method have been used to compute the effective potential for electrons at different surfaces of Al, Ni, Cu, Ag, and W. In each case, the average of the potential parallel to the surface is reproduced well by a simple model barrier with three adjustable parameters, with relatively small variations between different metals and surfaces. FLAPW calculations have also been used to examine the effects of chemisorption on the surface barrier. The results of this work provide a basis for the analysis of low-energy-electron-diffraction fine-structure and inverse-photoemission spectra.