Interaction of hydrogen and oxygen with a chlorine covered Ag(111) surface

Results of a study of changes in electron capture and loss rates in the interaction of hydrogen and oxygen atoms and anions with chlorine covered Ag(111) surfaces are reported for a wide range of coverages. Strong oscillatory changes in anion formation rates are observed as a function of chlorine coverage. These: changes are assigned to changes in local electronic structure and modifications in positions and widths of the anion levels at different phases of chlorine adsorption and in particular to interaction of the projectile with the adsorbed Cl(3p) levels. At high coverages, a higher electron capture probability is found, corresponding to the appearance of chloride islands.