Probing the role of (Nd, Ni) co-doping on structural and optical properties of nanocrystalline BiFeO3

Abstract

The pure and (Nd, Ni) co-doped BFO (Bi0.9Nd0.1Fe0.9Ni0.1O3) nanoparticles have been synthesized using the sol-gel combustion method. The phase purity and crystal structure of the samples are confirmed by the x-ray diffraction pattern. Rietveld refinement analysis is performed to calculate the lattice parameters, bond lengths, and bond angles. The crystal structure of the samples is found to be rhombohedral distorted perovskite structure with space group R3c. The crystallite size is calculated using both Scherrer’s relation and Williamson Hall approach and is found to increase with doping. FTIR studies reveal absorptions peaks at 547 cm−1 and 429 cm−1 respectively. These are the characteristic peaks of the FeO6 octahedra and hence confirm the formation of the BFO phase. The reflectance spectra show a peak at 305 nm in UV region and is transparent to the material in the visible region. The optical band gap has been estimated by using the Tauc’s relation and is found to be 2.92 eV for pure and 2.99 eV for (Nd, Ni) co-doped BFO.