FARADAY-EFFECT IN THIN AMORPHOUS MAGNETIC-FILMS

The Faraday effect in thin amorphous magnetic films has been investiga ted for the first time. The films of general composition FeCoNiSiB wer e deposited onto glass substrates by laser ablation of amorphous ribbo n targets in high vacuum. Since the films have been found to have in-p lane anisotropy the Faraday effect measurements were carried out under oblique incidence of 632.8 nm He-Ne laser beam. It has been establish ed that the Faraday rotation angle has a linear dependence on the film thickness in the range from 20 to 1300 Angstrom. The Verdet constant was estimated to be as high as 3 deg (Oe cm)(-1). This value is an ord er of magnitude higher than the known one for YIG at the same waveleng th. The comparative studies of Faraday and Kerr rotation under the sam e fields have been performed in different geometries. The experimental data were in a good agreement with the results obtained by theoretica l evaluations. It has been found that at a thickness exceeding 200 Ang strom, the Faraday effect in deposited films prevailed over the Kerr o ne. The Faraday effect in the produced films is attractive for designi ng thin-film miniaturized magnetic sensors on the basis of fiber optic s and optoelectronics. (C) 1997 Elsevier Science S.A.