Spin- and angle-resolved photoemission study of ultrathin Gd films on Fe(100)

Using spin-resolved photoemission with synchrotron radiation, we have studied the electronic structure of the Gd/Fe(100) interface. For Gd films up to one monolayer thickness, we find a high Gd 4f-electron spin polarization which is antiparallel to that of the Fe valence bands. This is the first direct observation of high Gd 4f-electron polarization. The main effect of the Gd adsorption on the Fe-derived valence bands is a depolarization. For thick Gd films (>35 A{}) the observed Gd 4f polarization is small even well below the Gd TC.