The role of doping on the structural and functional properties of BiFe1-xMnxO3 magnetoelectric ceramics

BiFeO3 is one of the few single-phase multiferroics, showing antiferromagnetic and ferroelectric ordering. Since the dielectric properties in the ceramic state of the pure BiFeO3 were rather poor and in order to stabilize the perovskite state and to induce ferromagnetism at room temperature, it was adopted the strategy of doping with rare earth or forming solid solutions. Substituting Fe with Mn in BiFeO3-based compounds is supposed cause better properties in terms of leakage current density and also to induce changes in the magnetic order of the system. In the present paper, the effect of Mn substitution on the dielectric and magnetic properties of the BiFe1-xMnxO3 ceramics has been studied. Homogeneous samples from microstructural point of view were obtained for all the compositions analyzed. The magnetic properties are strongly affected by the presence of Mn ions. The possible origin of these behavior is discussed in terms of phase purity, grain size and grain boundary phenomena. The extrinsic properties are impossible to be fully controlled by normal ceramic processing. By controlling the extrinsic contributions to the dielectric properties, the ceramic system might be a valuable multiferroic material for magnetoelectric applications. At room temperature the ceramic is a multiferroic, since it is ferroelectric and magnetically-ordered. (C) 2010 Elsevier B.V. All rights reserved.