Ferromagnetic resonance studies on (Co40Fe40B20)x(SiO2)1−x granular magnetic films

Magnetic properties of granular (Co₄₀Fe₄₀B₂₀)_x(SiO₂)_1−x   thin films (x=0.37-0.53$x=0.37-0.53$) have been studied by ferromagnetic resonance (FMR) technique. Samples have been prepared by ion-beam deposition of Co–Fe–B particles and SiO₂ on sitall ceramic substrate. The FMR measurements have been done for different orientations of DC magnetic field with respect to the sample plane. It was found that the deduced value of effective magnetization from FMR data of the thin granular film is reduced by the volume-filling factor of the bulk saturation magnetization. The overall magnetization changes from 152 to 515 G depending on the ratio of the magnetic nanoparticles in the SiO₂ matrix. From angular measurements an induced in-plane uniaxial anisotropy has been obtained due to the preparation of the film conditions as well.