Background removal in x-ray photoelectron spectroscopy: Relative importance of intrinsic and extrinsic processes

The shape of all major x-ray-excited peaks, including Auger transitions, from Cu, Ag, and Au are studied. The intensity contribution from inelastic (extrinsic) processes are removed. In all cases the primary excitation spectra thus determined are found to consist of a peak and a tail of (intrinsic) electrons which extends {~}50 eV below the peak energy. Beyond this energy essentially all measured intensity is accounted for without the use of adjustable parameters. The ratio of intrinsic to extrinsic contribution to the measured intensity is of the same order as previously found for the simple metals.