High in-plane magnetic anisotropy and microwave frequency performance of soft magnetic (Fe₅₀Co₅₀)_1-x(Al ₂O₃)_x films prepared by modified composition gradient sputtering

The fabrication and high-frequency ferromagnetic performances of (Fe ₅₀Co₅₀)_1-x(Al₂O₃) _x soft magnetic films (SMFs) were investigated. It is revealed that the modified composition gradient sputtering method dramatically improves the high-frequency soft magnetic properties of the as-prepared films. This method gives rise to a linearly increased distribution of compositions and residual stress. As a result, comparing with the samples prepared by conventional composition gradient sputtering (CGS) method, a very high and uniform ferromagnetic resonance frequency in excess of 5 GHz, high uniaxial magnetic anisotropic field, and low magnetic loss were obtained, which are particularly in favor of the integration between magnetic films and radio-frequency (RF) components.