Bandgaps, surface states and the anomalous neutralization of Li+ on (111) surfaces of noble metals

Abstract

The effect of progressive changes in the electronic structure of (111) surfaces of noble metals on neutralization of Li+ ions is studied in relation to recent study on electron transfer on nanoclusters dealing with electronic effects. Strong differences in electron transfer probabilities are revealed and the trends in these changes are related to the progressive changes of the band structure of Ag, Cu and Au surfaces. Experimental data reveal an anomalously high neutralization of ions on these high workfunction surfaces and an unusual ion energy dependence, suggesting a pronounced non-adiabatic character of the electron transfer process, not accountable in a ‘jellium’ model of resonant electron capture. We suggest a mechanism of capture involving non-resonant charge exchange from occupied surface states as well as a strongly reduced loss due to the presence of the L-bandgap.