Soft magnetic films play a core role in magnetic sensors and high frequency devices, due to the advantage of miniaturization, integration and standardization. Giant magnetoimpedance effect (GMI), an electromagnetic phenomenon with high signal intensity and field sensitivity, has potential applications. For high frequency electromagnetic devices, soft magnetic films with high saturation magnetization and high in-plane uniaxial anisotropy field have become very important research materials.
In this dissertation, FeNi/Cu/FeNi films without and with one or two NiZn-ferrite spacers were prepared by magnetron sputtering, and NiZn-ferrite layers were fabricated on the free surface of Fe-based amorphous ribbons for the research of GMI effect. Fe75.5Cu1Nb3Si3.5B7 films were deposited by oblique sputtering, and their high frequency magnetic properties were studied. Main results are as follows:
1. Influence of NiZn-ferrite spacers on GMI in FeNi/Cu/FeNi films: An enhanced GMI effect is observed in the multilayer film with one NiZn-ferrite spacer, while the GMI is not evidently enhanced in the multilayer film with two NiZn-ferrite spacers.
2. Influence of NiZn-ferrite spacers on GMI in Fe-based amorphous ribbons: After the NiZn-ferrite layer coating on the free surface of a Fe-based amorphous ribbon, an enhanced GMI effect was observed in the NiZn-ferrite modified ribbon at all measured frequencies.
3. Adjust of in-plane uniaxial magnetic anisotropy of Fe75.5Cu1Nb3Si3.5B7 films: Films deposited with different oblique angles show in-plane anisotropy. From the ferromagnetic resonance measurement, it is found that there exist double resonance peaks in the films.
4. Adjust of magnetic damping in obliquely sputtered Fe75.5Cu1Nb3Si3.5B7 films: For the films deposited with oblique angle from 3o to 32o, the effective damping parameter is increased with increasing oblique angle. The intrinsic damping parameter basically maintains the value of about 0.016 in the range of 3o to 26o. But when the oblique angle is 32o, the intrinsic damping parameter reaches 0.037.