We report an investigation of the bulk electronic properties of Fe in Fe Si1-x Gex (x=0, 0.11, 0.19, and 0.44) measured by high-resolution x-ray absorption spectroscopy at the Fe K edge, Fe Kβ x-ray emission, and 1s3p resonant x-ray emission spectroscopies. The emission data clearly show an increase in the magnetic moment when x increases from 0 to 0.44. This doping-induced spin transition is accompanied by the onset of the magnetic order at x≥0.2. The 1s3p resonant x-ray emission data reveal that the Fe 3d states exhibit a delocalized character, while no intermediate valence admixture takes place. This is at odd with the intermediate valence Kondo insulator model and rather supports the local density approximation band theory.
|Physical Review B - Condensed Matter and Materials Physics
|Published - 2008 Mar 5