NEGATIVE MOLECULAR-STATE FORMATION AND DISSOCIATION OF MOLECULES SCATTERED FROM NI(111) AND NI(111) + K SURFACES

Molecular ions of CO, and O2 CO2 are scattered at grazing incidence with an energy of 400 eV from clean Ni(111) and Ni(111) + K. Most of the scattered particles are neutralized molecules and neutral dissociation products. With increasing K-coverage the yield of negative ions and the dissociation of O2 and CO2 increases. In the case of Co and K adsorption has little influence on the electronic interaction with the surface. The CO2- ions observed are identified with corresponding negative molecular ions in chemisorption experiments, the O2- ions are possibly related to short lived intermediates in chemisorption. © 1990 Pergamon Press plc.