Ferroelectric-controlled magnetoelectric effect at the CrI3/HfO2 interface

The effective manipulation magnetic properties of two-dimensional magnets through electric field presents profound implications for spintronics. In this study, we investigate the ferroelectric-controlled magnetoelectric coupling within the CrI3/HfO2(111)/CrI3 heterostructure by using first-principles calculations. It is found that the magnetic moments of CrI3 are notably responsive to the polarization orientation-either directed towards (Pin) or away (Pout) from the interface. The polarization of HfO2 triggers the accumulation (depletion) of screening electrons at the Pin(Pout) interface, which affects the relative population of the exchange-split spin bands at the interface and thus results in the enhanced (reduced) total magnetic moments of the monolayer CrI3. The easy magnetization axis of CrI3 switches from an out-of-plane (Pout state) to an in-plane (Pin state) direction by the reversal of ferroelectric polarization of HfO2. Additionally, the Curie temperature (TC) of monolayer CrI3 is enhanced by 78% in the Pout state. This work provides useful guidelines for the study of interfacial magnetoelectric coupling and design of multiferroic devices.