The semiconductor to metal transition in FeSi1-xGex probed by high resolution X-ray absorption spectroscopy

The substituted system FeSi 1-x Ge x undergoes a semiconductor to metal transition at x∼0.25. We investigated the electronic structure for the x = 0, 0.19 and 0.44 compounds using X-ray absorption spectroscopy in the partial fluorescence yield mode (PFY-XAS) at the Fe K-edge. The position of the edge showed no x or temperature dependence, and agreed with that of metal Fe. These results are consistent with the band calculations.