Sol-gel synthesis and characterisation of (Nd, Cr) co-doped BiFeO₃ nanoparticles

Bi_0.95Nd_0.05Fe_{1– x}Cr_xO₃ (x = 0, 0.01, 0.03, 0.05) samples are synthesised by the sol-gel method. The variation in structure, magnetisation, electrical and photocatalytic properties by Cr doping at Fe site in Bi_0.95Nd_0.05FeO₃ samples is analysed. X-ray diffraction pattern confirms the formation of rhombohedral structure in all the samples. The crystallite size is calculated using the Scherrer relation and found to be in nanometre range. Kubelka-Munk theory is used to determine the direct band gap of the samples from reflectance spectra. The saturation magnetisation is found to enhance the concentration of chromium. Arrott-Belov-Kouvel plot confirms the ferromagnetic nature in the samples. The leakage mechanisms are studied to understand the influence of Cr concentration on the BFO. A good correlation exists between the leakage current and ferroelectric behaviour. Photocatalytic tests show degradation of methylene blue dye in the presence of H₂O₂. A drastic decrease in photocatalytic activity is observed with the concentration of Cr.