Origin of magnetic circular dichroism in soft x-ray fluorescence of Heusler alloys at threshold excitation

Abstract

The results of investigations of the Heusler alloys NiMnSb and Co2MnSb by magnetic circular dichroism in soft x-ray emission spectroscopy (SXEMCD) are presented. The data obtained are in a good agreement with theoretical calculations of x-ray emission. A very intense resonant inelastic peak in the Mn L3 spectra in the region of states above the nominal Fermi level was observed and attributed to x-ray reemission. The interplay between the theoretically predicted half-metallic character of the Mn 3d valence band and the Mn L2,L3 SXEMCD spectra is discussed.