High-energy photoemission in silver: resolving d and sp contributions in valence band spectra
We present high-resolution valence band and core level spectra of silver for photoelectron kinetic energies up to 8 keV. At these kinetic energies we estimate a surface contribution of less than 3%. Taking advantage of the favourable sp/d relative cross-sections, a comparison with the calculated density of states is presented. We observe an increasing photoemission intensity when approaching the Fermi level, which we assign to a free-electron-like character in the 5p-band, whereas the principal s-like contribution is located at the bottom of the d-band. The difference between measured and calculated values of the sp/d cross-section ratio is discussed.