High In-Plane Magnetic Anisotropy and Microwave Frequency Performance of Soft Magnetic (Fe$_{50}$Co$_{50}$)$_{1-{\rm x}}$(Al$_{2}$O $_{3}$) $_{\rm x}$ Films Prepared by Modified Composition Gradient Sputtering

The fabrication and high-frequency ferromagnetic performances of (Fe
$_{50}$
Co
$_{50}$
)
$_{1-{\rm x}}$
(Al
$_{2}$
O
$_{3}$
)
$_{\rm x}$
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.