Effect of Zr doped Bi site in bismuth ferrite on crystal structure and optical bandgap

Bismuth ferrite (BiFeO3) is one of multiferroic which is currently in great demand for research because of its small bandgap. Bi1-xZrxFeO3 (BZFO) where x = 0.01, 0.02, and 0.03 samples have been prepared by the sol-gel method to know the effect brought by Zr doping in site Bi. Structural and optical properties of samples have been studied using XRD, FTIR, Raman, and UV-Vis characterizations. X-ray diffraction study showed the samples have a hexagonal structure with R3c space group. To further explore the structure and study of dopant in material, Raman spectroscopy has been employed. There are 10 modes of Raman shift which confirm the structure of BZFO, where the modes shift towards the lower wavelength. The measurement of various bond formation and vibrations between the atom of BZFO were carried out with Fourier Transformed Infrared (FTIR) spectra. The results showed vibrations of FeO6 and BiO6 at peak 534.26 cm-1 an 431.21 cm−1. Absorbance and reflectance spectra were obtained from UV-Visible diffuse spectroscopy. The bandgap was determined from reflectance spectra using Kubelka-Munk method and was plotted using the Tauc plot. The bandgap is found to be slightly increased with the doped of Zr.