Oxygen-tuned exchange interaction by boosting uncompensated magnetic moments in ferromagnet/antiferromagnet interfaces

Modulating exchange-coupling interaction at ferromagnet (FM)/antiferromagnet (AFM) interfaces is essential for constructing low-power magnetic random memories, logic devices, and topological electronic devices. Currently, most effective tunability focuses on the regulation of uncompensated magnetic moments by controlling the attributes of AFM materials, such as component, roughness, texture, or stress state. Here, we report a method of oxygen-tuned uncompensated magnetic moments to tailor the exchange-coupling interaction. By inserting an ultrathin oxide (MgO, $\mathrm{Hf}{\mathrm{O}}_{2}$, or ${\mathrm{Al}}_{2}{\mathrm{O}}_{3}$) into the NiFe/IrMn interface to regulate the chemical state of NiFe, both the magnetic anisotropy of NiFe and uncompensated magnetic moments of AFM were effectively modified. The oxidation product strongly depended on the metal-O dissociation energy of these oxides, leading to various tunability effect of exchange-coupling interaction. By appropriate formation of antiferromagnetic FeO, obvious enhancement of exchange-coupling interaction was achieved by boosting the uncompensated magnetic moments, accompanied by a maximal 60% increment in exchange bias. These findings provide insights for regulating exchange-coupling interaction and constructing efficient spintronic (topological) devices.