STRUCTURE OF THE GROUND AND EXCITED STATES IN THE Co2FeSi HEUSLERВ ALLOYВ ACCORDING TO THE RESONANTВ PHOTOEMISSIONВ DATA
V. I. Grebennikov1,2, A. Buling3, M. Neumann3, V. V. Marchenkov1, T. V. Kuznetsova1
1Institute of Metal Physics, Ural Division, Russian Academy of Sciences, Ekaterinburg, Russia
2Ural State University of Railway Transport, Ekaterinburg, Russia
3OsnabrГјck University, Germany
Keywords: semimetal ferromagnetic, resonant photoemission, selective excitation of elements, X-ray spectroscopy, photohole effects, multiparticle excitations, spin polarization
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 2 p 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 2 р 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.
DOI: http://dx.doi.org/10.1134/S002247661503018X
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