SCATTERING OF SWIFT MOLECULES, H-2 AND CO2, FROM METAL-SURFACES

Abstract

Molecular ions and neutral molecules are scattered at 500 eV and at grazing incidence from metal surfaces. H-2(+) and CO2+ are subject to charge exchange processes which lead in part to dissociation. In the case of CO2+ evidence for negative molecular ion formation is found. When using neutral H-2 and CO2 only in the case of CO2 is charge capture observed, i.e. negative ions are found. Potassium `'poisons'' the dissociation of H-2, on Pd. These findings are supported by comparison of different metals, Ni(110), Pd(110) and Pd(110) covered with a monolayer of K. The dissociation probability of H-2(+) and H-2(0) decrease at the K-covered surface, in the cases of CO2+ and CO20 an increase is found. CO2+ on Pd(110) K dissociates completely.