Gigantic magnetic field polarization and magnetoelectric coupling in a ferrimagnetic oxide CaBaCo4O7

TL;DR

This study reveals large electric polarization and strong magnetoelectric coupling in CaBaCo4O7, a ferrimagnetic oxide, demonstrating significant potential for magnetoelectric applications and ferrotoroidic behavior.

Contribution

It reports the discovery of giant polarization and magnetoelectric effects in CaBaCo4O7, a non-collinear ferrimagnetic oxide with potential ferrotoroidic properties.

Findings

Large electric polarization of 17 mC/m^2 at 10K

Magnetic field induces an 8 mC/m^2 polarization change at 62.5K

Supports ferrotoroidic behavior in the material

Abstract

The single crystal study of CaBaCo4O7, a non collinear ferrimagnet (TC=64K), with a polar orthorhombic space group (Pbn21) between 4 K and 293 K, shows the appearance below TC of a large electric polarization along its c axis, reaching 17mC.m-2 at 10K. At 62.5K, a magnetic field driven giant variation of polarization, P(9T)-P(0T)=8mC.m-2, is observed. Moreover, the present magnetoelectric measurements, are fully consistent with the m'm2' magnetic point group, strongly supporting that this oxide is also ferrotoroidic. This ferrimagnetic oxide, which belongs to the '114' structural family, opens an avenue for the search of new magnetoelectrics.