Metal–insulator type nano-granular soft magnetic thin films investigations on mechanism and applications

Abstract Metal–insulator type nano-granular soft magnetic thin films have been note-worthily developed as a new soft magnetic material for electric devices that demand further miniaturization and higher frequency operation. The formation of nano-granular structure is strongly related to the magnitude of heat formation (Δ H ) of intergranule materials. Forming a larger Δ H allows a clearer granular structure to be obtained. The HRTEM observation reveals that neighboring granules in NGSM films contact at the considerable points, and the soft magnetism is explainable in terms of random anisotropy model for nano-crystalline materials. Addition of Pd in Co–O-based NGSM films enhances the compositional range of soft magnetic film and their H k up to 400 Oe. A large H k in NGSM films means that the films exhibit an excellent μ–f response.