Multilayer films (MLF's) composed of FePt ordered alloy and Pt were prepared by an ion beam sputtering method. X-ray diffraction in a low angle region indicated that the structural anomaly, leading to the absence of the multilayer periodicity, was seen in the case of the FePt layer thickness (dFePt) round 50Å. The interplanar spacing along the perpendicular direction to the film plane increases for dFePt around 50 Å. Furthermore, in the case of dFePt around 50Å, the existence of an antiferromagnetic phase was also confirmed from the shift of the hysteresis loops at 4.5K in field cooling. Therefore, we consider that Pt-rich FePt alloy is formed in the FePt/Pt MLF's with dFePt around 50Å. The spectral shapes of the θK and ηK spectra show a significant change for dFePt > 50 Å and dFePt < 50 Å. This fact suggests that the change in the electronic structure of the FePt/Pt MLF's occurs around dFePt = 50Å. accompanied by the structural anomaly.
