Effect of bias voltage on kerr rotation angle in amorphous TbFeCo films prepared by RF-sputtering

X-ray photoelectron studies on amorphous TbFeCo ternary alloy films prepared by rf-sputtering, with several bias voltages, have been made under UHV conditions. The XPS binding energies were identical to those of the pure elements and the alloy within the experimental accuracy. The Fe XPS spectra of amorphous TbFeCo films increased and approximated to the Fe XPS spectrum of FeCo binary alloy film with increasing a bias voltage. The Co XPS spectra of amorphous TbFeCo films, however, were independent of the increase of bias voltage. It was found that, in amorphous TbFeCo film with the same composition, the film prepared under a higher bias voltage had a larger Kerr rotation angle. It was concluded that the state change of Fe in amorphous TbFeCo film caused the difference of Kerr rotation angle.