Anomalous hall effect in Pt/Tb3Fe5O12 heterostructure : effect of compensation point

Abstract

Atomically-flat thin films of ferrimagnetic insulator Tb3Fe5O12 (TbIG) were grown on (1 1 1)-oriented Gd3Ga5O12 (GGG) substrates by pulsed laser deposition. Magnetic measurements indicated the easy magnetic axis of TbIG film was out-of-plane, as a result of the substrate-induced compressive in-plane strain within the film. The temperature dependence of anomalous Hall effect (AHE) in Pt/TbIG bilayer was systematically studied with the applied magnetic field normal to the film plane, with square hysteresis AHE loops being observed. Reversal of AHE sign occurred twice between 10 K and room temperature, one at 50 K and another around 220 K, the latter of which was accompanied by complex magnetization switching behavior. The peculiar behavior of AHE loop around 220 K is closely related to the compensation point of TbIG. On the other hand, the sign change at 50 K was attributed to the modification of Pt electronic structure by TbIG. Our results highlight the relation between the AHE of Pt and magnetic properties of TbIG, which can be used for probing the magnetism in TbIG.