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Electron emission
Electron surface collisions
Metal surfaces
Surface states
Electron transfer
Abstract:
We observe a strong influence of molecular vibration and surface temperature on electron emission promoted by the de-excitation of metastable CO (a 3Π) on a clean Au(111) surface using a molecular beam surface scattering apparatus. The de-excitation is independent of incidence translational energy. These observations appear incompatible with existing theories of metastable particle de-excitation on metal surfaces, which are based on the Auger effect. Instead, they strongly suggest a mechanism involving formation of a transient anion whose lifetime is similar to the vibrational period of the CO molecule.