Determination of the Surface Conductivity of Ultrathin Metallic Films on Si(111) by High-Resolution Electron-Energy-Loss Spectroscopy

Temperature-dependent (20-300 K) electron-energy-loss measurements of the quasielastic peak for {~}2.5-10 {} of evaporated Au and Pd on Si(111) are presented, which, together with a theory of the electron scattering from metallic layers, permit the determination of dc conductivities. Metallic films, {~} 10 {} thick, are found to have large temperature-independent resistivities dominated by surface scattering and imperfections. An unusual temperature-dependent resistivity is found for Pd on Si which is suggested to arise from a phase transition near the interface.