Anomalous Hall effect at a PtOx/Co interface

We study the anomalous Hall effect at a PtOx/Co interface. We extracted the intrinsic and extrinsic contributions to the anomalous Hall effect in SiO2/Co/SiO2 and PtOx/Co/SiO2 films by measuring temperature dependence of the anomalous Hall resistivity. The result shows that the intrinsic anomalous Hall effect in the PtOx/Co/SiO2 film is almost identical to that in the SiO2/Co/SiO2 film. In contrast, the extrinsic anomalous Hall effect is clearly different between the SiO2/Co/SiO2 and PtOx/Co/SiO2 films. The anomalous Hall effect for various Co-layer thicknesses t at various temperatures reveals that the extrinsic anomalous Hall resistivity shows a t-1 dependence in the PtOx/Co/SiO2 film, while it is almost independent of t in the SiO2/Co/SiO2 film. This result demonstrates the extrinsic anomalous Hall effect originating from the PtOx/Co interface. Our results show that both the side-jump and skew-scattering mechanisms contribute to the interfacial anomalous Hall effect, which can be attributed to the formation of Co-O bonds and electron scattering by Pt impurities at the PtOx/Co interface.