Structural and electrical properties of La-modified BiFeO3–BaTiO3 composites

Abstract

In the present investigation, La-modified solid solutions of BiFeO3 (BFO) and BaTiO3 (BT) in different molar ratios [i.e., (Bi0.5−x La x Ba0.5)(Fe0.5Ti0.5)O3, with x = 0.0, 0.05, 0.10 and 0.15)] have been synthesized using a solid-state reaction route. Structural and electrical properties of single phase (with minor secondary phase) of BFO–BT system have been studied in details to understand their ferroelectric and other properties. Preliminary X-ray diffraction analysis confirms the formation of a new system, which is different from that of its parent compounds. Substitution of a small amount BaTiO3 into BiFeO3 enhances dielectric and ferroelectric responses and reduces electrical leakage or tangent loss. The ac conductivity obeys Jonscher’s universal power law. The electrical behavior of the samples was investigated by impedance spectroscopy in a wide temperature range (25–525 °C) at different frequency (1 kHz–1 MHz). The impedance spectroscopy of the materials also confirms the origin of the relaxation mechanism in the system.