Spin Reorientation Transition and Magnetization Reversal Mechanism of Gd Doped FeCo High-Frequency Soft Magnetic Thin Films

Abstract

The magnetic FeCoGd thin films with various sputtering power from 10 to 30 W were fabricated on glass substrates by magnetron co-sputtering. The crystal structure of as-deposited FeCoGd thin films was investigated by X-ray diffraction. And an increasing trend of grain size with the increasing sputtering power was shown. When sputtering power is below 30 W, the films exhibited obviously in-plane uniaxial magnetic anisotropy, and the in-plane magnetic anisotropy field Hkdecreased with increasing deposition power. Moreover, good high frequency characteristics were obtained. The magnetization reversal mechanism has been investigated via the in-plane angular dependences of the magnetization and the coercivity. The experimental data points indicated that the magnetization reversal mechanism of FeCoGd film with in-plane uniaxial anisotropy is domain-wall depinning and coherent rotation when the applied field is close to the easy axis and hard axis, respectively. A spin reorientation transition phenomenon was observed when deposition power is larger than 30 W. A stripe domain structure for the sample with 30 W deposition power was developed due to a dominated perpendicular magnetic anisotropy.