Characteristic energy losses of 8 keV electrons in liquid In-Al and In-Bi alloys

Abstract

Measurements have been made of the characteristic energy losses of 8 kev electrons in a series of liquid In-Al and In-Bi alloys in order to avoid the confusing effects of phase mixtures present in most similar studies of solid alloy systems. Loss spectra were measured in a reflection-type scattering geometry with total electron scattering angles of 15° and 70°. Two principal energy loss peaks, identified as being due to surface plasmon and to volume plasmon excitation, were found to vary as a function of alloy composition in each system. Deviations from the variation expected from a simple free-electron model could be interpreted in some cases in terms of an interband electronic transition occurring near the measured volume and surface energy-loss peaks. For bismuth-rich In-Bi alloys and for indiumrich In-Al alloys the transmission energy and oscillator strength could be estimated and shown as a function of composition.