Influence of Deposition Cycle and Magnetic Annealing on High-Frequency Magnetic Properties of the [Co90Fe10/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 α and real part of permeability μ'. 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 4πM
_s
= 13.06 kG, in-plane uniaxial magnetic anisotropy fields H
_k
= 42 Oe, easy-axis coercivity H
_ce
= 2.8 Oe, ferromagnetic resonance frequency f
_r
= 2.25 GHz, and real permeability μ' = 255.