The interaction of small molecules with Pd and K covered Pd surfaces at energies from 200 keV to 6 keV

Abstract

In the energy range of 200 eV to a few keV small molecules are scattered at grazing incidence from Pd(110) and Pd(110) covered with a monolayer of K. The experimental setup provides ions and neutrals as primary particles and the time-of-flight analysis of the scattered particles includes both ions and neutrals. Depending on energy and K coverage, dissociation and scattering of the molecules is found. At low energies and one monolayer K the survival of H 2 is very high and decreases with increasing kinetic energy. At the clean surface the dissociation is high and increases with increasing energy. The data analysis shows that at low energies electronic processes are most important for the fate of the molecules, whether they are neutrals or ions. With increasing kinetic energy, vibrational and rotational excitations of the molecules contribute increasingly to dissociation. Classical trajectories calculations reveal interesting details of these processes.