Studies on the multiferroic properties and impedance analysis of (La, Cu) BiFeO3 prepared by sol-gel method

Abstract

Perovskite BiFeO3 (BFO), and Bi1-xLaxFe0.98Cu0.02O3 (x ≤ 0.05) multiferroic ceramics were prepared by conventional sol-gel method. The influence of (La, Cu) co-doping on the structure, morphology, magnetic, ferroelectric and dielectric behavior were studied comprehensively. X-ray diffraction confirmed that the BFO samples possess rhombhedral structure. The crystallite size, lattice constant, etc were affected by La doping. Ferromagnetic properties were distrubed due to external doping. Enhanced ferroelectic properties like increased remanant polarization and reduced leakage current were achieved by La-substitution. Significant enhancement of dielectric constant may be attributed to Maxwell-Wagner effect. Impedance spectroscopy analysis suggests the effect of grain and grain boundary on the electrical properties of the BFO ceramics. Cole-Cole plots specifies non-Debye type of behavior. Enhanced dielectric constant, reduced loss and decreased leakage current of (La, Cu) doped BFO suggest these ferrites to be promising room temperature perovskite multiferroic materials for lead-free photovoltaic devices.