Electronic structure of Al3Ni and AlNi3 alloys

Experimental Al KL(23)V and Ni LMM Auger and high-resolution valence band XPS spectra of Al3Ni and AlNi3 alloys are presented and compared to the corresponding spectra of pure metals. The spectra are interpreted in terms of the results of the discrete-variational (DV)-X alpha cluster MO model using atomic Auger transition probabilities. Good agreement has been obtained between the theory and experiment concerning the energy widths of the spectra. For Al3Ni the total number of electrons at the Fermi level obtained from the calculations agrees better with the experimental value than those from previous calculations. In the case of the alloys, the calculated charge transfer is small (<0.4 electrons), playing only a minor role in the filling of the Ni d band. The hybridization between the Ni d and Al s and p bands can be deduced from the reduction of the Al s and p DOS at the Ni d resonance energy. Our results suggest that for these alloys the corresponding Auger matrix elements do not depend on the Auger transition energy. The Ni LMM spectra of the alloys demonstrate the localization of the Ni d band.