Multiferroic Bismuth ferrite nanocomposites as a potential photovoltaic material

Abstract Bismuth ferrite (BFO) is one of the few materials which is multiferroic (antiferromagnetic and ferroelectric) at 25°C. In this work, we synthesized multiferroic BFO via sol-gel method and observed its structural and optical properties. While synthesizing BFO, the annealing temperature was at 550°C. X-ray diffraction (XRD) analysis exhibited a rhombohedral crystal structure. Rietveld refinement via MAUD software has been employed to obtain the structural parameters of BFO. Williamson-Hall (W-H) plot method is used to analyze the XRD data. We obtained crystallite size of 37.61 nm through W-H plot analysis. Using the crystallographic information file, we measured the bond angle and bond length of BFO nanoparticles. BFO nanoparticles with both uniform distribution and spherical shape was observed in Field Emission Scanning Electron Microscopy (FESEM). The average particle size of 157 nm was measured from FESEM analysis. The atomic % of Bismuth (Bi), Oxygen (O) and Iron (Fe) elements in BFO was obtained from Energy dispersive spectroscopy. The optical bandgap energy (Eg) of BFO was calculated using UV-Vis-NIR, and we found the bandgap energy of 2.04 eV for BFO annealed at 550°C. This bandgap energy makes BFO a potential photovoltaic material.