SOFT-X-RAY FLUORESCENCE STUDY OF BURIED SILICIDES IN ANTIFERROMAGNETICALLY COUPLED FE SI MULTILAYERS/

Soft-x-ray fluorescence spectroscopy has been employed to obtain infor mation about the Si-derived valence-band states of Fe/Si multilayers. The valence-band spectra are quite different for films with and withou t antiferromagnetic interlayer exchange coupling, demonstrating that t hese multilayers have different silicide phases in their spacer layers . Comparison with previously published fluorescence data on bulk iron silicides shows that the Fe concentration in the silicide spacer layer s is substantial. Near-edge x-ray-absorption data on antiferromagnetic ally coupled multilayers in combination with the fluorescence data dem onstrate unambiguously that the silicide spacer layer in these films i s metallic. These results on the electronic structure of buried layers in a multilayer film exemplify the wide range of experiments made pos sible by high-brightness synchrotron sources.