  Electric field control of the magnetic state in ferrimagnets holds great
promise for developing spintronic devices due to low power consumption. Here,
we demonstrate a non-volatile reversal of perpendicular net magnetization in a
ferrimagnet by manipulating the electric-field driven polarization within the
Pb (Zr0.2Ti0.8) O3 (PZT)/CoGd heterostructure. Electron energy loss spectra and
X-ray absorption spectrum directly verify that the oxygen ion migration at the
PZT/CoGd interface associated with reversing the polarization causes the
enhanced/reduced oxidation in CoGd. Ab initio 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.
