Electric Control of Exchange Bias via Oxygen Ionic Migration in Co/NiO/Ta/HfO ₂ Resistive Switching Devices

Magneto-ionics, an emerging field controlling magnetism via electric-field-driven ion migration, faces a critical bottleneck: slow switching speed. Utilizing the inherent ion migration in resistive switching (RS) devices offers a potential solution for the fast electric control of magnetism. In this work, we inserted a 3 nm-thick Ta layer between the NiO and HfO 2 layers to prepare the Co/NiO/Ta/HfO 2 device, which exhibited repeatable and reversible RS performance. Under negative voltage, the device switches from a high-resistance state (HRS) to a low-resistance state (LRS), accompanied by an increase in coercivity ( H C ) and a decrease in exchange bias field ( H E ). In contrast, positive voltage resets the device to HRS, with H C decreased and H E increased simultaneously. The above electric control of exchange bias (EB) is attributed to oxidation/reduction of the interfacial Co layer in combination with oxygen ions migrating into/out of the NiO layer during the RS cycling process. This improved magneto-ionic control method by using a multiresistive-layer structure provides a clue to developing multifunctional spintronic devices with low energy consumption.