Enhancement of anomalous Hall effect in SrIrO3/NiCo2O4 heterostructures induced by interfacial charge transfer
The anomalous Hall effect (AHE) in strongly correlated transition metal oxide (TMO) systems provides a platform for investigating coupled spin, charge, orbital, and lattice degrees of freedom, and enables spin current-driven magnetization switching. However, enhancing the AHE in such systems remains a critical challenge. This work systematically investigates the electronic transport properties of SrIrO3/NiCo2O4 (SIO/NCO) heterostructures. The AHE of SIO/NCO heterostructures is enhanced by an order of magnitude compared to ferrimagnetic NCO single films. The enhancement becomes more pronounced as the SIO sublayer thickness decreases, which is attributed to large strain exacerbating interfacial charge transfer. X-ray photoelectron spectroscopy reveals variations in binding energies and concentrations of electronic states, confirming the charge transfer mechanism. The AHE in SIO/NCO heterostructures arises from the synergistic effect of the intrinsic mechanism dominated by Berry curvature and the extrinsic mechanism caused by impurity scattering. These findings advance the reliability of TMO-based spintronic devices.