Photoemission Studies of the Noble Metals. II. Gold

Abstract

New photoemission data have been obtained from evaporated films of gold in the range of photon energies between 5 and 21.2 eV. With the exception of a single direct transition, all the optical transitions appear to fit a nondirect model; consequently, it has been possible to construct an optical density of states (ODS) for gold in the region \ifmmode\pm\else\textpm\fi{}11.6 eV about the Fermi level ${E}_{F}$. Two broad peaks dominate the valence ODS. These are centered at about 3.5 and 6 eV below ${E}_{F}$. The higher-lying peak is resolved into a doublet with peaks at 3.0 and 3.8 eV. The two broad peaks correlate well with peaks observed in soft-x-ray photoemission. Positive correlation is also found with band calculations. The electron-electron scattering length for gold has been calculated as a byproduct of the analysis relating the ODS to the photoemission data, and detailed quantitative agreement is found between the calculated scattering length and Kanter's experimental values in the range between 5 and 11 eV above the Fermi level. This quantitative agreement between the calculated and experimental scattering length provides a useful cross-check in support of both the experimental data and the model used to analyze them.