Maltose-assisted sol–gel synthesis, structural, magnetic and optical properties of multiferroic BiFeO3 nanopowders

Multiferroic BiFeO 3 nanopowders are synthesized through a sol–gel route using the environment-friendly and non-toxic maltose as the complexing and reducing agent. A high content of hydroxyl groups is found to be critical in the preparation of phase-pure BiFeO 3 materials. Fourier transform infrared spectroscopy, thermogravimetric analysis and differential scanning calorimetry reveal that the optimal calcination temperature of BiFeO 3 precursor is about 450 °C in the synthesis, leading to the formation of phase-pure and well-crystallized BiFeO 3 nanopowders with sizes being about 40 nm. Magnetic measurements illustrate the ferromagnetic behavior of BiFeO 3 nanopowders at room temperature. The maximum and remanent magnetizations of the nanopowders are about 0.657 and 0.048 emu/g, respectively, under the magnetic field of 50 kOe. Moreover, the energy band gap of the nanopowders is approximately 2.27 eV, confirming their strong absorbance of the visible light. Graphical