Structural, Magnetic, and Electrical Properties in Ba-Doped BiFeO3 Prepared Using a Sol–Gel Route

Abstract

Ba-doped bismuth ferrite with chemical composition Bi_1 – xBa_xFeO₃ (x = 0.1, 0.2, 0.3, 0.4, and 0.5) nanoparticles were synthesized by the wet chemical sol–gel method. The substitution of Ba²⁺ at the Bi³⁺ site was meant to improve the resistivity, enhance magnetic properties, and suppress the impurity phases of BiFeO₃. The samples synthesized were later subjected to X-ray diffraction (XRD) analysis, Field emission scanning electron microscope (FESEM) with energy dispersive spectroscopy (EDS), Magnetic measurements using a vibrating sample magnetometer (VSM) and dielectric analysis along with ferroelectric measurements. XRD patterns obtained at room temperature revealed that the obtained samples are single-phase materials. The crystallite size showed a decrease from 46 to 24.58 nm and the unit cell volume was found to increase following Vegard’s law. The increase in tolerance factor from 0.855 to 0.908 was reported for increasing doping concentrations. The FESEM and SEM micrographs indicate that the particles are rhombohedral-hexagonal in shape. The EDS results confirm the presence of the desired elements Ba, Bi, Fe, and O and the proportionate composition of various elements present as well. The room temperature M–H curve and the M–H curve at 3 K also confirm the enhancement in magnetization with increasing doping concentration. The room temperature dielectric measurements reveal the improving resistivity of the samples with increasing doping concentrations. The increasing grain resistance as revealed by the Cole-Cole plots indicate the decreasing conductivity of doped BFO samples. The P–E measurements confirm the ferroelectric nature of the material.