Ferroelectric and ferromagnetic properties of Mn-doped 0.7BiFeO₃-0.3BaTiO₃ solid solution

Binary solid solutions 0.7BiFeO₃-0.3BaTiO₃-x wt.% MnO₂ (x = 0, 0.2, 0.3, and 0.5) were prepared by a traditional ceramic process. All ceramic samples show single perovskite phase. The effect of manganese doping on structure, dielectric, ferroelectric and ferromagnetic properties, and resistivity was investigated. Results show that Mn-dopant can improve the sintering ability of the materials when MnO₂ content is below 0.3 wt.%. When MnO₂ content exceeds 0.3 wt.%, the sintering ability is weakened and the phase structure of 0.7BiFeO₃-0.3BaTiO₃ solid solution changes from rhombohedral into tetragonal phase. With increasing concentration of MnO₂, the resistivity increases at first and then decreases. Whereas the coercive electric field decreases at first and then increases, the remanent magnetization M_r increases and the coercive magnetic field decreases.