Negative ion resonances of O-2 adsorbed on Ag surfaces

This article gathers together a collection of recent experimental studies o f the adsorption of oxygen on (001), (110) and (111) crystal surfaces of si lver with special emphasis on the negative ion states of this model system for oxygen adsorption. These investigations were performed in a network ent itled 'Negative ion resonances of adsorbed molecules' supported financially by the European Union within the 'Human capital and mobility programme'. T he kinetics and thermodynamics of adsorption are investigated by measuring the sticking coefficient and by thermal desorption spectroscopy (TDS). The vibrational spectra provided by high-resolution electron energy loss spectr oscopy (HREELS) are used to analyse the adsorbed species (physisorbed and c hemisorbed) in the case of O-2 On Ag(110) and on Ag(111). The mechanisms of Inelastic electron scattering by adsorbed O-2 are further investigated wit h special reference to the negative ion resonances (NIRs), formed by electr on capture, which are involved in the electron-molecule collision process.