Influence of leaching and soaking duration on the phase stability, microstructural, optical, and electrical properties of bismuth ferrite

Synthesis of pure phase BiFeO3(BFO) is of utmost importance for varied multiferroic and optical applications, but the actual practical realization of pure BFO is hampered by several parameters. Herein, a facile sol-gel method incorporated with a rigorous leaching and washing procedure was employed as a novel approach to successfully synthesize pure BFO. The influence of leaching and soaking duration on the phase stability, microstructural, electrical, and optical properties were investigated. Characterization of the samples were carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR), and UV spectrophotometer. All the electrical measurements were done using LCR meter. XRD and Rietveld analysis verified the pure phase BFO crystallites formation. A good agreement between the calculated and observed data confirmed the phase purity of the synthesized BFO. Leaching was found to be an effective approach for phase purification as it can successfully rule out the impurity peaks as evident from the XRD result. SEM images revealed agglomeration of grains with an increase in soaking duration. FTIR spectra confirmed the presence of bending and stretching vibrations of various bonds present in the samples. AC conductivity, dielectric constant, dielectric loss, resistance, reactance, and impedance were measured and possible explanations of their variation with soaking duration were discussed. The absorbance spectra were studied and the optical band gap of the samples lies in the visible region which can ultimately be exploited for use in photocatalytic applications.