Electric field control of the perpendicular magnetization switching in ferroelectric/ferrimagnet heterostructures

<h2>Summary</h2> Electric field control of the magnetic state in ferrimagnets holds great promise for developing spintronic devices with lower power consumption due to their reduced net magnetization compared with that in ferromagnets and the lack of heating induced in the case of current-induced magnetization switching. Here, we study heterostructures made from piezoelectric and ferrimagnetic materials (Pb (Zr_0.2Ti_0.8) O₃ (PZT)/CoGd) and demonstrate the non-volatile reversal of the perpendicular net magnetization in the CoGd ferrimagnet by manipulating the electric-field-driven polarization within the PZT layer. Electron energy loss spectra and the X-ray absorption spectrum directly verify that the oxygen ion migration at the PZT/CoGd interface associated with reversing the polarization causes enhanced or reduced oxidation in CoGd. <i>Ab initio</i> calculations further substantiate that the migrated oxygen ions can modulate the relative magnetization of Co/Gd sublattices, facilitating perpendicular net magnetization switching. Our findings offer an approach to effectively control ferrimagnetic net magnetization, holding significant implications for ferrimagnetic spintronic applications.