Partial densities of states of alloys: Cu sub 3 Au.

The photon-energy dependence of the photoelectric cross section of the 4d and 5d elements is sufficiently strong to allow the isolation of the partial densities of states of many alloys and intermetallic compounds. For photon energies above 150 eV the valence band spectra of Cu sub 3 Au are dominated by bulk and surface Cu 3d states. At photon energies below 50 eV the spectra correspond very closely to the d-band density of states of the surface Au atoms. XPS spectra at normal take- off angle contain approximately equal contributions from bulk Au and Cu d-states.