MICROSTRUCTURE AND MAGNETISM OF （Fe₆₅Co₃₅）_x（SiO₂）_1-x NANO-GRANULAR FILM

(Fe₆₅Co₃₅)_0.42（SiO₂）_0.58 granular film consisting of FeCo nanoscale magnetic granules embedded in SiO₂ matrix was fabricated by radio frequency （RF） magnetron sputtering. Excellent soft magnetic properties with anisotropy field Hk = 3 820 Am-1, coercivity in easy axes low as to as 143 Am^-1 and resistivity up to 13.4 mΩ·cm were obtained after the sample was annealed in a magnetic field at low temperature. At a frequency lower than 0.7 GHz, the real part μ′ of complex permeability of this sample is above 100 and the FMR frequency is as high as 1.8 GHz, implying a high cut-off frequency for high frequency applications, which makes it promising in the applications in high frequency device and anti-jamming technology. It was proved by ferromagnetic resonance that the good soft magnetic properties in this sample come from the ferromagnetic intergranular exchange coupling.