EXPERIMENTAL AND THEORETICAL SPECTRA FROM THE 4P CORE LEVELS OF YTTRIUM

We have carried out an investigation of the surface core level shift and the photoemission from the 4p core level at the (0001) surface of yttrium. We calculated the electronic structure surface at the surface/vacuum interface using the self-consistent field, linearized muffin-tin orbital method in a supercell geometry. We find that the 4p eigenvalues for atoms in the first and second layers are shifted by +0.56 eV and -0.18 eV, respectively, from the bulk value. We used the layer-dependent potential functions in first-principles calculations of the photocurrent and the theoretical spectra are in excellent agreement with the experimental observations. © 1990.