Evidences of magneto-electric coupling in BFO-BT solid solutions

Multiferroic properties viz antiferromagnetism and ferroelectricity of BiFeO3 (BFO) has been reported to be enhanced by forming solid solution with BaTiO3 (BT) designated by BFO-BT. In the present investigations a few compositions in the solid solution (1−x)BiFeO3-xBaTiO3 (x = 0.10, 0.15 and 0.30) have been synthesized by solid state ceramic route. Structural, magnetic and electrical properties of single phase solid solution compositions of BFO-BT have been studied in detail to understand their multiferroic properties. Powder X-ray diffraction confirms the formation of solid solution. All the samples show ferromagnetic behavior at room temperature having low coercivity and high saturation magnetization. Substitution of BaTiO3 into BiFeO3 enhances dielectric and ferromagnetic responses and reduces electrical leakage. It suggests a coupling between ferroelectric and magnetic parameters near the antiferromagnetic-paramagnetic transition, which is responsible for the broad frequency dependent dielectric maxima. The impedance spectroscopy also confirms the origin of the structure.