Direct Observation of Strong Anomalous Hall Effect and Proximity-Induced Ferromagnetic State in SrIrO3

Abstract

The 5d iridium-based transition metal oxides have gained broad interest because of their strong spin–orbit coupling, which favors new or exotic quantum electronic states. On the other hand, they rarely exhibit more mainstream orders like ferromagnetism due to generally weak electron–electron correlation strength. Here, a proximity-induced ferromagnetic (FM) state with TC ≈ 100 K and strong magnetocrystalline anisotropy is shown in a SrIrO3 (SIO) heterostructure via interfacial charge transfer by using a ferromagnetic insulator in contact with SIO. Electrical transport allows to selectively probe the FM state of the SIO layer and the direct observation of a strong, intrinsic, and positive anomalous Hall effect (AHE). For T ≤ 20 K, the AHE displays unusually large coercive and saturation field, a fingerprint of a strong pseudospin–lattice coupling. A Hall angle, σxyAHE/σxx, larger by an order of magnitude than in typical 3d metals and an FM net moment of about 0.1 μB/Ir, is reported. This emphasizes how efficiently the nontrivial topological band properties of SIO can be manipulated by structural modifications and the exchange interaction with 3d TMOs.