Li+ ion neutralization on Ag layers grown on Cu(1 1 1)

Electron transfer processes in the neutralization of Li+ ions on Ag layers grown on Cu(1 1 1) are investigated in quest of quantum confinement effects. Neutralization probabilities in the scattering of Li+ for incident ion energies in the 300 eV to 2 keV range are reported for Ag coverages ranging from 0.15 ML to 5 ML. Results are compared to those for Ag(1 1 1) and Cu(1 1 1) surfaces of bulk crystals. Although existing studies of the characteristics of Ag layers on Cu(1 1 1) indicate significant differences in electronic structure as a function of film thickness, the electron transfer probabilities we measure are found to be very close to those for bulk Ag(1 1 1). These results are commented on the basis of existing models and earlier studies of Li ion neutralization on various metals.