Surface Plasmon Excitation Of Au And Ag In Scanning Probe Energy Loss Spectroscopy

摘要

We explore the incident energy dependence of the electronic excitation spectra of Au and Ag films in scanning probe energy loss spectroscopy (SPELS) and also high resolution electron energy loss spectroscopy. We show that the spectra obtained in SPELS depend strongly on the incident electron beam energy. In the case of Au, interband transitions mask the surface plasmon unless the field emission voltage is reduced to ～100 V, whereas there is a clear surface plasmon peak above 300 V for Ag.