Electron energy loss spectroscopic investigation of polycrystalline Au, Pd and a Pd-Au alloy

Electron energy loss spectra (ELS) obtained from palladium, gold and a palladium-gold (69-31 at.%) alloy as a function of primary beam energy (100-1150 eV) are presented in this study. The spectra are complex, so unambiguous identification of the features is difficult. Nevertheless, some interband transitions and bulk and surface features can be identified. The objective of this study is to test the efficacy for ELS to detect electronic interactions between gold and palladium in the alloy. This was done by comparing the experimental alloy ELS spectra with ELS spectra calculated from the pure metal spectra. These sets of spectra are quite similar indicating that the electronic interaction between alloyed Pd and Au is small. This is expected since both Au and Pd are not very chemically reactive. The small differences apparent in the comparison provide information about the nature of the electronic interaction which is consistent with data obtained in photoemission studies.