Multi-resistance state tuned by interfacial active Pt layer in a perpendicular Hall balance

Abstract

The effect of interfacial Pt layer on multi-resistance states in perpendicular Hall balance with core structure of [Co/Pt]n/NiO/[Co/Pt]n multilayers was systematically investigated. By inserting an ultrathin Pt layer between [Co/Pt]n and NiO spacer, resistance states and the Hall resistance ratio (HRR) were successfully tuned. Our results indicate that the inserted ultrathin Pt layer plays a crucial role on spin dependent transport properties, achieving a HRR of up to 30,900%. Furthermore, the resistance in Hall balance can be smoothly altered among 2-, 3-, and 4-states by optimizing the ultrathin active Pt layer. Pt catalyst with high electronic activity, as measured by X-ray photoelectron spectroscopy (XPS), provides a novel approach for modifying the interfacial orbital hybridization, thus leading to a tunable resistance states and HRR value.