Bismuth Ferrite Nanopowders Prepared by Sol-Gel

摘要

BiFeO_3 powders were prepared by sol-gel process and calcined at different temperatures. The DTA curve shows an obvious exothermic peak near 480.5°C, the temperature close to BiFeO_3 formation temperature, which is agreement with the XRD results (450°C). After calcining at 600°C for 1h, XRD spectra has the emergence of several sharp diffraction peaks, compared with the standard XRD spectrum of the crystal BiFeO_3. As the calcining temperature increased, the diffraction peak intensity of the XRD spectra of BiFeO_3 gradually increased and the diffraction peaks became sharply, indicating that the grain size gradually became larger. There is a clear endothermic peak near 825.1°C, which is the α phase to β phase transition from the knowledge of the phase diagram and in good agreement with the reported Curie temperature.