ELECTRONIC-STRUCTURE OF AMORPHOUS FEXY100-X ALLOYS

The electronic structure of amorphous FexY100-x alloys (31 less than o r equal to x less than or equal to 87) co-evaporated under UHV conditi ons has been investigated using photoelectron spectroscopic methods (U PS, XPS). The results are compared to calculations based on the local spin-density (LSD) approximation and a molecular dynamic modeling of t he amorphous structure. The evolution of the valence band structure as a function of the alloy composition is discussed in relation to previ ously studied amorphous FexZr100-x alloys. A good agreement between th e experimental spectra and the theoretical predictions is found in the Fe-rich regime. The discrepancy observed in Y-rich samples is attribu ted to a tendency for segregation of Y and Fe atoms, as indicated by t he molecular dynamic simulations and small-angle neutron diffraction e xperiments.