Voltage Control of Perpendicular Magnetic Anisotropy by Resistive Switching through a Ta/HfO₂ Bilayer

Voltage control of perpendicular magnetic anisotropy (VCPMA) by resistive switching (RS) is an approach for manipulating perpendicular magnetization, which is of significant importance in realizing energy-efficient and high-speed spintronic devices. However, simultaneously achieving good RS performance and effective VCPMA poses a considerable challenge. In this study, we investigated the VCPMA in the RS device with a stack of Pt/Co/Ta/HfO 2 /Pt. With the aid of Ta’s strong oxygen affinity and the high mobility of oxygen ions in the resultant Ta-oxide layer, the insertion of an appropriately thick Ta layer can not only improve the RS performance but also modulate the PMA effectively. When a negative voltage is applied and increased to the “set” voltage, oxygen ions may migrate from the HfO 2 layer to the Ta layer, resulting in a transition from the high resistance state (HRS) to the low resistance state (LRS) and a weakening of PMA as well. On the contrary, when a positive voltage is applied and increased to the “reset” voltage, oxygen ions will return to the HfO 2 layer, leading to the device switching from LRS to HRS and partial recovery of PMA. This work provides a clue to the design of energy-efficient spintronic devices.