  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.
