Anregung von Volumen- und Oberflächenplasmaschwingungen in Al und Mg durch mittelschnelle Elektronen

Abstract

Dispersion and scattering cross section of the bulk plasma losses of Al and Mg are compared with plasma theory. The low lying Mg loss shows an asymmetric intensity distribution for non-normally incident electrons and an angular dependence of intensity as expected from the theory of surface losses. In very thin Al films, coupling effects between the two opposite surfaces are found, causing some new properties of the surface losses. Especially a thickness dependent dispersion of the surface loss is measured which is quite different from that of the bulk losses and characteristic for surface excitation.