Interaction time dependence of electron tunneling processes between an atom and a surface

Results of a study of electron transfer processes in the interaction of fluorine and hydrogen with Ag(111) are reported for a wide range of interaction times. For long interaction limes the yield of H-, resulting from resonant electron exchange, is larger than expected for a jelliumlike metal surface with a similar work function. For short interaction times, the yields follow the trend for jelliumlike surfaces. These results confirm the predictions of the theoretical work [Borisov et nl. Phys. Rev. Lett. 80, 1996 (1998)] on electron transfer on surfaces with an L band gap; In the case of F-, significant effects were, however, not observed. [S0031-9007(99)09233-9].