THEORY OF TEMPERATURE-DEPENDENT PHOTOEMISSION IN 3D-BANDFERROMAGNETS - APPLICATION TO NI(111)

Abstract

The influence of both electron correlation and phonons on the temperature-dependence of ultraviolet photoemission spectra of ferromagnetic Ni is investigated. The spin- and temperature-dependent photo-current is calculated in the framework of a generalized one-step model of photoemission. Phonons are taken into account via temperature-dependent phase-shifts. The hole-state of photoemission is described by an energy-, spin- and temperature-dependent self-energy, which rests on a combination of density functional theory and a generalized Hubbard model. Here we calculate spin-polarized and temperature-dependent photoemission spectra for Ni(111) and compare with experimental data. As already our results for Ni(110) showed, the theoretical photoemission calculations are in excellent agreement with the experiment. In particular for Ni(111) an inverse exchange splitting may be identified.