Aspects of Structural and Multiferroic Properties of A- (15% Gd) and B-Site (5–15% Cr) Doped Perovskite BiFeO3 Nanoparticles

This report focuses on the investigation of multiferroic properties of 15% Gd and (5–15) % Cr co-doped Bismuth Ferrite (BFO) nanoparticles prepared by sol–gel method. The synthesized pure BFO has shown to be R3c rhombohedral crystal structure which partially transforms to Pnma orthorhombic crystal structure with increasing Cr dopant in co-doped samples. The crystallite size was found to vary from 68 to 22 nm depending on doping level. SEM images exhibited uniform nanoparticles and the average size of particles was shown to vary from 263 to 114 nm which is comparatively higher than that obtained from XRD results due to agglomeration effects. Ferroelectric tests exhibited a significant reduction in polarization in doped BFO under an applied field of ± 15 kV/cm. In contrast, the magnetic measurement showed a substantial improvement in ferromagnetic properties of the synthesized samples compared to un-doped one. A prominent exchange anisotropy effect was also observed in all the samples at room temperature. In addition, co-doped BFO samples demonstrated a significant reduction in band gap energy from 1.88 to 1.68 eV.