High frequency characteristics and magnetic properties of CoFeN/native-oxide multilayer films

This article reports on the relations between the high frequency characteristics and magnetic properties of multilayer CoFeN/native-oxide films prepared by radio frequency reactive magnetron sputtering in mixed argon and nitrogen gas atmosphere and exposure to oxygen in a sequence. The [CoFeN(20)/native-oxide]20 multilayers exhibit excellent soft magnetic properties in the as-deposited state, e.g. easy axis coercivity (Hc) below 1 Oe and 4πMs of ∼22kG. The in-plane uniaxial anisotropy field (Hk) is as high as 67 Oe. This large anisotropy field significantly enhances the ferromagnetic resonance frequency (fFMR) to ∼3GHz.