Magnetoelectric Effect Dependent on Electric Field Direction in a Pyroelectric Ferrimagnet CaBaCo${}_4$O${}_7$

This study investigates the dependence of the static magnetoelectric (ME) effect on the external field direction in the pyroelectric-ferrimagnet CaBaCo${}_4$O${}_7$, a topic that remains largely unexplored compared to dynamical nonreciprocal ME effects. We measured the magnetization with respect to the inherent polarization and found that an external electric field stabilizes the ferrimagnetic phase when applied parallel to the polarization, and destabilizes it when antiparallel. These results clearly demonstrate the electric-field-direction dependent control of the static ME effect, suggesting a new route to enhancing ME effects in pyroelectric-magnetic materials.