Faraday effect dispersion in multilayered Fe/SiO2 films

Abstract Dispersion and field dependencies of the Faraday effect (FE) have been investigated in multilayered Fe/SiO 2 films. Two series of samples were prepared by rf sputtering: in each series the Fe layers thickness were constant at 10 and 15 A and the SiO 2 layers thickness was varied in wide ranges from 1.5 to 90 A. Strong changes of FE dispersion depending on the thickness of SiO 2 layers have been found in comparison with bulk Fe or with homogeneous Fe films: while for monolayered homogeneous Fe films (both 15 and 200 A in thickness) a monotonous increase of the FE has been observed with increasing wave length, similar to bulk Fe samples, for multilayered films the FE increase occurred when the wave length decreased. Therewith, the greater the SiO 2 layer thickness (i.e., the less the volume Fe concentration in a sample) the stronger was the difference FE spectra of multilayered and homogeneous films. The results are discussed in terms of the FE theory in granular materials.