Dielectric, electrical and magnetic properties of La doped BiFeO₃–PbZrO₃ composites

Abstract

The composites of 0.5(BiLa_yFe_1−yO₃)–0.5(PbZrO₃) [y = 0.05, 0.10, 0.15 and 0.20] were synthesized through solid-state reaction technique. The X-ray diffraction data confirms the rhombohedral structure of the above systems at room temperature. From the SEM, it is shown that the grains were inhomogeneously distributed over the surface of the composites. The dielectric constant and loss of the composites increased with rise in temperature. The low remanent polarization (0.005, 0.006, 0.008, and 0.004 μC/cm²) for 0.5(BiLa_yFe_1−yO₃)–0.5(PbZrO₃) [y = 0.05, 0.10, 0.15 and 0.20] respectively shows the weak ferroelectric nature. The Nyquist plot showed the contribution of bulk effect and slight indication of grain boundary effect. The presence of temperature dependent relaxation process occurs in the material. The activation energies calculated from the ac conductivity using least square fitting. The dc and ac conductivity increases with rise in temperature. The ac conductivity spectrum obeyed Johnscher universal power law. The low remanent magnetization was found to be 0.010, 0.009, 0.008 and 0.005 emu/gm for 0.5(BiLa_yFe_1−yO₃)–0.5(PbZrO₃) [y = 0.05, 0.10, 0.15 and 0.20] respectively.