Effects of Core-Hole Screening on Spin-Polarised Auger Spectra from Ferromagnetic Nickel

TL;DR

This paper investigates how core-hole screening influences the spin polarization of Auger electrons in ferromagnetic nickel, revealing significant reductions in local magnetic moments due to screening effects.

Contribution

It introduces a detailed theoretical model for core-hole screening effects on spin-polarized Auger spectra in ferromagnetic nickel, incorporating electron correlations via a multi-band Hubbard approach.

Findings

Core-hole potential causes strong screening in Ni valence band.

Local magnetic moment decreases by a factor of 5-6 due to screening.

Implications for spin polarization of Auger electrons are discussed.

Abstract

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