Effects of core-hole screening on spin-polarised Auger spectra from ferromagnetic Ni

We calculate the spin- and temperature-dependent local density of states fo r ferromagnetic Ni in the presence of a core hole at a distinguished site i n the lattice. Correlations among the valence electrons and between valence and core electrons are described within a multi-band Hubbard model which i s treated by means of second-order perturbation theory around the Hartree-F ock solution. The core-hole potential causes strong screening effects in th e Ni valence band. The local magnetic moment is found to be decreased by a factor of 5-6. The consequences for the spin polarisation of CVV Auger elec trons are discussed.