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

Below TC, the single-crystal study of CaBaCo4O7, a noncollinear ferrimagnet (T-C = 64 K) with a polar orthorhombic space group (Pbn2(1)) between 4 and 293 K, shows a large change in the electric polarization along its (c) over right arrow axis reaching Delta P = 17 mC/m(2) at 10 K. At 62.5 K, a magnetic-field-driven giant variation in polarization P(9 T) - P(0 T) = 8 mC/m(2) 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.