Structure of the ground and excited states in the Co2FeSi Heusler alloy according to the resonant photoemission data

Abstract

The electronic structure of the ground and low-energy excited states of the Co2FeSi Heusler alloy is investigated by the methods of X-ray absorption spectroscopy (XAS) and resonant X-ray photoelectron spectroscopy (RXPS). The orbital and spin magnetic moments of the iron and cobalt atoms are determined in a 0.05 T magnetic field. A comparative analysis is given of two amplifier channels of the valence band photoemission at the resonant excitation of the 2p level: elastic and Auger electron emission. A decrease in the magnetic moment of the atom leads to a qualitative change in the resonant photoemission spectrum. The valence electron shake-up at a sudden appearance of a 2p core photohole on the iron atoms leads to multiple formations of low-energy electron-hole pairs and gives rise to continuous losses in the XPS and XAS spectra. Shake-up in the cobalt atoms with great probability gives rise to one electron-hole pair with an energy of 4 eV, which is manifested as a satellite band in the above mentioned spectra. The mentioned feautures are closely related to semimetal ferromagnetism.