Microwave electromagnetic characteristics of FeCoB-SiO2 nano-granular magnetic films

FeCoB-SiO2 nano-granular films were fabricated by alternately deposited multilayers using radio frequency magnetron sputtering. Microstructures and morphology were analyzed by x-ray diffraction, scanning probe microscope and transmission electron microscope. Magnetic parameters were measured by vibrating sample magnetometer. The electrical resistivity was measured by a direct current four-probe method, and the complex permeability was measured by microwave resonance cavity. The mechanism of the effect of microstructures and content of SiO2 on electromagnetic characteristics was also discussed. Results show that these films have good performance at high frequencies. mu' can be larger than 70 at 2 GHz. Thus, the films may be applied to the micromagnetic devices or microwave absorbers in the GHz range.