Unusual anomalous Hall effect in the ferrimagnetic GdFeCo alloy

We have investigated the anomalous Hall effect (AHE) of a ferrimagnetic GdFeCo film with perpendicular magnetic anisotropy. In the vicinity of magnetization compensation temperature TM, the peak structure or triple loop of the Hall resistance loops is mainly caused by the opposite magnetic moments of the two sublattices of Gd and FeCo, and that can be explained by the mechanism of the two-channel AHE. Furthermore, we demonstrated that the transport properties of the GdFeCo film can be manipulated by ionic liquid gating. When the gate voltage is −4 V, the TM of the GdFeCo film was changed up to 29 K. Our research provides experimental evidence for the design of novel electronic devices.