Effect of Nd and Nb co-doping on the structural, magnetic and optical properties of multiferroic BiFeO3 nanoparticles prepared by sol-gel method

BiFeO 3 , BiFe 0.95 Nb 0.05 O 3 and Bi 1− x Nd x Fe 0.95 Nb 0.05 O 3 ( x =0.0, 0.05, 0.10, 0.15 and 0.20) nanoparticles are successfully synthesized via a tartaric acid-assisted sol-gel technique for the first time. The effect of Nd and Nb co-doping on the structure, morphology, and magnetic and optical properties is investigated. X-ray diffraction (XRD) and Raman measurements demonstrate that Nd 3+ ions and Nb 5+ ions co-doping at A and B-sites of BiFeO 3 can result in a structural transformation (from single rhombohedral phase ( R 3 c ) to two coexisting phases ( R 3 c and Pbam)). The morphology of the nanoparticles seems to be approximately cubic, and by the co-doping, the size of the nanoparticles decreases from ~132 to ~35   nm. Notable improvement in the remanent magnetization of the sample with x =0.15 is observed with a value of 0.285   emu/g, being 20 times higher than that of the undoped sample (BiFeO 3 ). A decrease in the optical band gap is also observed in the Nd and Nb co-doped nanoparticles, indicating their favorable potential in photocatalytic applications.