XPS studies of Co-sputtered Gd-Fe alloys

Abstract
The electronic structure of co‐sputtered Gd x Fe1−x alloys (0?x?1) has been studied by means of monochromatized X‐ray photoemission (XPS). For the amorphous Gd‐ and Fe‐rich compositions, respectively, the conduction band spectra, including the 4f levels of Gd, are surprisingly very similar to those of crystalline Gd and Fe. These spectra of the alloys appears to be well described as a linear superposition of those of the pure elements. Small Gd→Fe charge transfer upon alloying is inferred from the unchanged Fe 2p core‐level line shape asymmetry and the small shift in energy of the Gd‐ and Fe core levels. On the basis of a simple relationship between charge transfer and altered interatomic separation distances, the charge transfer in the amorphous alloys appears to be too small, compared to the crystalline phases, in order to account for the magnitude of the Fe moment.