Spin reorientation transition and near room-temperature multiferroic properties in a W-type hexaferrite SrZn1.15Co0.85Fe16O27

In this Letter, we investigate the magnetic and multiferroic properties of a W-type hexaferrite SrZn1.15Co0.85Fe16O27. Due to the strong planar contribution to the anisotropy provided by Co2+ ions, this hexaferrite shows a spin reorientation transition from easy-axis to easy-cone at 302 K, which is different from the onset temperature of ferroelectric polarization, 275 K. By applying magnetic field, a remarkable drop of polarization is observed, suggesting a large magnetoelectric effect in this multiferroics. The difference between spin reorientation and ferroelectric phase transition temperature as well as the origin of magnetoelectric effect are discussed