Magnetic Anisotropies of Fe/MgO Multilayers Determined by Submillimeter Wave FMR

Abstract

The dependences of the resonance fields and the FMR absorption intensities of Fe/MgO multilayered films on the thickness of the Fe layer have been obtained by the submillimeter wave FMR using the pulsed magnetic field up to 15 T at 4.2 K. The magnetic anisotropy of each film, which is determined by the frequency dependence of the FMR with the aid of the results of the magnetization measurements, can explain the angular dependence of the FMR completely. The dependence of FMR absorption intensity on the thickness of Fe layer, however, turned out to be rather different from the results of the magnetization measurements.