Effects of HfO2/Co interface and Co/HfO2 interface on anomalous Hall behavior in perpendicular Co/Pt multilayers

Effects of the HfO2/Co interface and the Co/HfO2 interface on thermal stability of anomalous Hall effect (AHE) in perpendicular Co/Pt multilayers have been studied. It is observed that thermally stable AHE behavior cannot be obtained in perpendicular Co/Pt multilayers with the HfO2/Co interface, mainly due to Co-Pt interdiffusion during annealing. In contrast, thermally stable AHE feature is observed in perpendicular Co/Pt multilayers with the Co/HfO2 interface despite Co-Pt interdiffusion, which is owing to the enhancement of the side jump and intrinsic contributions to the AHE through interfacial modification after annealing.