Adsorbate Core Ionization as Primary Process in Electron-and Photon-Stimulated Desorption from Metal Surfaces

Abstract

It is shown conclusively that electron impact ionization of the C $1s$ and O $1s$ core levels of CO adsorbed on W(100) leads to C${\mathrm{O}}^{+}$ and ${\mathrm{O}}^{+}$ desorption, respectively, and that soft-x-ray photons induce the same processes by an intrinsic photoeffect. Disintegration of the adsorption complex which becomes multiply charged by Auger decay of the core hole is assumed as explanation.