Interfacial chemical structure-modulated anomalous Hall effect in perpendicular Co/Pt multilayers

The enhancement of anomalous Hall effect (AHE) has been observed by inserting a Hf metallic layer at the Co/HfO2 interface in perpendicular HfO2/[Co/Pt]2/Co/HfO2 multilayers. It is displayed that the saturation anomalous Hall resistivity is 46% larger than that in Co/Pt multilayers without Hf insertion. Meanwhile, thermally stable AHE property is obtained in perpendicular HfO2/[Co/Pt]2/Co/Hf/HfO2 multilayers. The X-ray photoelectron spectroscopy analysis reveals that the improved AHE originates from the modulation of chemical states at the Co/HfO2 interface, owing to the insertion of the Hf layer.