Distance-Dependent Relaxation Shifts of Photoemission and Auger Energies for Xe on Pd(001)

Photoelectrons and Auger electrons from Xe in adsorbed multilayers of Xe on Pd(001) as well as on spacer layers of Kr on Pd(001) exhibit well-resolved increases in kinetic energy with decreasing distance from the surface (2-28 {}), allowing a direct labeling of the layers. These relaxation shifts for core-hole excitations (0.9-2.1 eV) and for Auger excitations (3.3-6.6 eV) are well described by an image potential, where the position of the image plane agrees within 0.2 {} with local-density functional theory.