Role of heat formation on soft magnetic properties and structure of metal-insulator type nano-granular magnetic films

In this study the magnetic properties and the microstructure of several granular films, which contain the insulating matrix with different magnitude of heat of formation ΔH, were investigated and a guide in obtaining excellent high frequency soft magnetic film was found. Nano-granular films were prepared on glass substrate by Ar+O₂ reactive sputtering using Co₈₅ME₁₅ alloy targets (ME: Ge, Sn, Si, Al, Dy, Sm, Y). High resolution transmission electron microscopy and small angle X-ray scattering were used for determination of the film microstructure. Magnetic measurements were conducted on a vibrating sample magnetometer. Results showed that saturation magnetization of Co-ME-O films gradually increased with the magnitude of ΔH of ME-O compound. On the other hand, the electrical resistivity decreased with increasing ΔH of ME-O compound films. These intrinsic factors were attributed to the structure change and segregation of film structure during deposition.