Gigantic magnetic-field-induced polarization and magnetoelectric coupling in a ferrimagnetic oxide CaBaCo 4 O 7
Résumé
Below TC, the single-crystal study of CaBaCo4O7, a noncollinear ferrimagnet (TC=64 K) with a polar orthorhombic space group (Pbn21) between 4 and 293 K, shows a large change in the electric polarization along its →c axis reaching ΔP=17 mC/m2 at 10 K. At 62.5 K, a magnetic-field-driven giant variation in polarization P(9 T) − P(0 T) = 8 mC/m2 is observed. Moreover, the present magnetoelectric measurements are fully consistent with the m′m2′ magnetic point group. This ferrimagnetic oxide, which belongs to the “114” structural family, opens an avenue for the search for new magnetoelectrics.