Ferroelectric properties of BiFeO3 films grown by sol–gel process

Several methods have been used to prepare ferroelectromagnetic BiFeO3 films. In this paper, we adopted a sol–gel process to fabricate BiFeO3 films on indium tin oxide (ITO)/glass substrates. X-ray diffraction pattern indicated that the samples are randomly oriented. Cross section scanning microscopy showed that the thicknesses of both films were about 1.2 μm and no apparent diffusion between the BiFeO3 films and ITO/glass substrates. Remnant polarization of 2.0 and 1.75 μC/cm2 were identified by the measuring of electric hysteresis loops for the films annealed at 500 and 600 °C respectively at an applied field of 108 kV/cm. Dielectric property and loss factor were investigated as a function of frequency. In addition, magnetism was detected at 77 K.