Sm-mediated dielectric characteristics and tunable magneto-electric coefficient of 0.5Bi1-xSmxFe0.95Mn0.05O3-0.5PbTiO3 composites

摘要： Magneto-electric multiferroic composites have gained a lot of interest these days mainly due to extensive potential of coupling between ferroelectric and magnetic orders. In this work, we present a series of 0.5Bi1-xSmxFe0.95Mn0.05O3 ? 0.5PbTiO3 (x = 0.00, 0.03, 0.06, 0.09, 0.12 and 0.15) composites, prepared by sol-gel auto-combustion and solid state reaction method to explore the tunability of magneto-electric coefficient. X-ray diffraction confirmed the rhombohedraly distorted cubic perovskite and tetragonal structures of BiFeO3 and PbTiO3, respectively. Ferroelectric loops showed that leakage current can be tuned and reduced by Sm-doping. Magnetic analysis showed switching of antiferromagnetic behaviour into weak ferromagnetic behaviour. Saturation and remanent magnetization were also calculated exhibiting an increasing trend with increasing Sm contents. Synthesized composites showed the non-linear frequency dependent dielectric response which was explained on the basis of Maxwell Wagner theory. Time varying conductivity was probed on the basis of polaron mechanism. The optimized composite reveal an enhanced magneto-electric coupling as compared to that of pure BiFeO3 which makes them feasible for the fabrication of multifunctional devices.