Progress of Relaxor Multiferroic Materials

The multiferroic material, which shows the coexistences of multi ferroic orders (ferroelectricity, ferromagnetism or ferroelasticity), can realize the mutual control of the electric and magnetic signals, and becomes one of the hottest research topics.The long-range ferroelectric or ferromagnetic order may be broken in compositionally disordered systems.In this situation, it is posssible that materials display relaxor behavior.Multiferroic materials possessiong at least one ferroic relaxor character can be named as relaxor multiferroics.The polarization (or magnetization) is very sensitive to the applied electric field (or magnetic field).Besides, the magnetoelectric coupling effect of relaxor multiferroics is different from that of multiferroics with long ferroic orders.In this paper, the most recent and important theoretical and experimental advances in this new research field are reviewed.Firstly, basic physical concepts of the relaxor ferroic orders and the different mechanism of the magnetoelectric coupling effect on materials are introduced with the coexistence of relaxor ferroelectric ordering and relaxor magnetic ordering.Then, the recent researches on two sorts of the relaxor multiferroics, including perovskite (PbB 1 B 2 O 3 based and BiFeO 3 based) and non-perovskite (Bi-layered based and improperly ferroelectric based) structural materials, are reviewed.Finally, the further development of relaxor multiferroics is prospected.