Influence of Deposition Cycle and Magnetic Annealing on High-Frequency Magnetic Properties of the [Co 90 Fe 10 /Ta] n Multilayer Thin Films

In this paper, a series of [Co 90 Fe 10 /Ta] n multilayer thin films with various deposition cycles n were prepared by magnetron sputtering. The crystal structure, top-surface topography, and static and dynamic magnetic properties of [Co 90 Fe 10 /Ta] n multilayer thin films were investigated systematically. The results showed that the deposition cycle n has slight impact on the high-frequency magnetic performance of the multilayer thin films except damping coefficient $\alpha$ and real part of permeability $\mu '$ . Moreover, we studied the influence of magnetic annealing temperature ( $T_{A}$ ) on high-frequency soft magnetic properties of [Co 90 Fe 10 /Ta] 15 multilayer thin films. It was found that saturation magnetization, coercivity, in-plane uniaxial magnetic anisotropy field, damping coefficient, and real part of permeability were all highly dependent on $T_{A}$ . When $T_{A}$ = 250 °C, the [Co 90 Fe 10 Ta] 15 multilayer thin film exhibited a relatively good comprehensive performance: saturation magnetization $4\pi \text{M}_{s} = 13.06$ kG, in-plane uniaxial magnetic anisotropy fields $H_{k}=42$ Oe, easy-axis coercivity $H_{\mathrm{ ce}} =2.8$ Oe, ferromagnetic resonance frequency $f_{r} =2.25$ GHz, and real permeability $\mu '= 255$ .