Exchange bias in multiferroic BiFeO3 and YMnO3 multilayers: One more parameter for magnetoelectric manipulation

A multiferroic BiFeO3 and YMnO3 multilayer film was deposited on an SrTiO3:Nb substrate using the pulsed laser deposition method. A large perpendicular exchange bias was observed, arising from the cycloid spin structure of the BiFeO3. In addition, at room temperature the film displays a larger magnetic moment than BiFeO3 and YMnO3, as well as ferroelectricity with good retention capability. Large exchange biasing, controlled by the magnetic field cooling history, will introduce one more parameter into the magnetoelectric control of multiferroic multilayers.