Charge-mediated voltage modulation of magnetism in Hf_0.5Zr_0.5O₂/Co multiferroic heterojunction

Abstract We construct the Hall-bar device with the size of several hundred nanometers based on the HZO/Co multiferroic heterojunction. A remarkable voltage-controlled magnetism is observed in the device that possesses both ferroelectric property and perpendicular magnetic anisotropy (PMA). The nucleation field and coercivity can be modulated by voltage pulse while saturation field keeps stable. The non-volatile and reversible voltage-controlled magnetism is ascribable to interfacial charges caused by ferroelectric polarization. Meanwhile, the effective anisotropy energy density (K u) can also be controlled by voltage pulse, a decrease of 83% and increase of 28% in K u are realized under -3 V and 3 V pulse, respectively. Because the energy barrier is directly proportional to K u under a given volume, a decreased or enhanced energy barrier can be controlled by voltage pulse. Thus, it is an effective method to realize low-power and high-stability magneto-resistive random-access memory (MRAM).