Thickness dependence of high-frequency magnetic properties in the oriented hcp-CoIr soft magnetic films with negative magnetocrystalline anisotropy

The c-axis oriented hcp-Co83Ir17 soft magnetic thin films with in-plane uniaxial anisotropy and negative magnetocrystalline anisotropy (Kugrain) were fabricated at 500 °C, and thickness dependence of their high-frequency magnetic properties was investigated. Both the saturation magnetization and Kugrain are improved compared with those of the samples fabricated at room temperature in previous reports. As the introduction of negative Kugrain, the natural resonance frequency is improved without affecting the initial permeability. With CoIr thickness increasing from 55 nm to 270 nm, the initial permeability decreases slightly; the natural resonance frequency increases and then changes little; the damping constant decreases gradually.