Ultraviolet photoelectron spectroscopy of the valence bands of some Au alloys

Ultraviolet photoelectron spectra taken with 40.81-eV photons are presented for three series of Au alloys: AuGa, AuIn, and AuCd. The results are discussed with reference to similar work on a series of Ag alloys previously reported and are also compared with x-ray photoelectron spectroscopy data. The results are consistent with the previous work on Ag alloys in that the Au 5d doublet width and splitting are (i) independent of the secondary or alloying metal, and (ii) strongly dependent on the mean number of nearest Au neighbors. The behavior of the Au 5d bandwidth, as a function of Au concentration, as measured here using He II radiation, differs significantly from that measured previously using x-ray photoelectron spectroscopy. This difference cannot be attributed wholly to the difference in linewidth of the two-photon sources or to surface enrichment of the samples. The similar variations of the Ga, In, and Cd d bands as a function of Au concentration are discussed with reference to previous work on the alloys of AgIn and AgCd