Structure and soft magnetic properties of Fe-Co-Ni-based multicomponent thin films

Abstract

Soft magnetic thin films with suitable uniaxial anisotropy and high saturation magnetization are required for high frequency applications, since the ferromagnetic resonance frequency (fFMR) is proportional to the multiplication of the saturation magnetization and anisotropy magnetic field. In this study, multicomponents of Fe-Co-Ni-based soft magnetic thin films were deposited on the Si substrate by radio frequency (RF) magnetron sputtering with various Ar/N2 ratios at room temperature. The composition, crystal structure, surface morphology, and magnetic domain were analyzed. Without nitrogen doping, the domain of the magnetic thin film was arranged randomly. The effect of N2 content in the thin film on the magnetic properties was evaluated and further discussed. Magnetic properties, including saturation magnetization (Ms) and coercivity (Hc), were determined. The saturation magnetization of the undoped magnetic thin film was around 1.3 T. However, when the nitrogen was added, the magnitude of the anisotropy field could reach 30 Oe, while the saturation magnetization was around 1 T. It is expected that the derived magnetic thin film is a promising candidate for potential usage in high frequency inductors.