Polarization-Dependent Resonances in Electronically Induced Ion Desorption via Adsorbate-Core Excitations on Metal Surfaces

Abstract

Yield curves of molecular and fragment ions desorbed from covalent adsorbates on metals by photon-stimulated adsorbate-core excitation show distinct resonances, whose symmetries can be determined from polarization dependences. Threshold resonances for shakeup excitations followed by spectator Auger decay are particularly desorption efficient. The influences of Coulomb localization of the multiply valence-excited final state, its repulsive nature, and its separation from the substrate are discussed.