We discuss the role of the electronic correlation in determining the line shapes of valence-band photoemission and Auger spectra of Ni silicides. Theoretical one-particle spectra, with correlation effects included by a perturbation approach to a degenerated Hubbard Hamiltonian, are compared with experimental energy-distribution curves. It is shown that for these compounds the electronic correlation is of crucial importance for describing valence-band photoemission. We also present the experimental line shapes of Ni L3VV transitions and compare them with theoretical two-hole spectral densities. It is concluded that a band-theoretical approach can account for some important features of the experimental Auger spectra, but multiplet effects should be included for a more detailed description.
Correlation effects in valence band spectra of Nickel Silicides / Bisi, Olmes; CALANDRA BUONAURA, Carlo; DEL PENNINO, Umberto; P., Sassaroli; Valeri, Sergio. - In: PHYSICAL REVIEW. B, CONDENSED MATTER. - ISSN 0163-1829. - STAMPA. - 30:(1984), pp. 5696-5703.