Structural, magnetic and optical properties of BiFeO3 synthesized by the solvent-deficient method

Bismuth ferrite (BiFeO3, BFO) powders were synthesized by a simple and cost-effective solvent-deficient method using bismuth nitrate, iron nitrate, and ammonium bicarbonate as the only precursors. Single phase BiFeO3 powder was fabricated after the Bi:Fe ratio was adjusted and after the precursor mixture was calcined for one hour at 600 degrees C. We investigated the formation reactions, crystal structure, particle size distribution, magnetic and optical properties of synthesized BiFeO3. X-ray diffraction revealed the formation of well-crystallized BFO nanocrystallites starting at a temperature of 450 degrees C. BiFeO3 powder calcined at 600 degrees C showed very weak ferromagnetism at room temperature which is different from the linear M-H relationship in bulk BiFeO3 ceramics. The remnant magnetization value (Mr) was found to be 5 x 10(-3) emu g(-1) and a coercive field value (Hc) nearly 500 Oe. The UV-visible spectra showed maximum adsorption at similar to 464 nm with a derived bandgap value of 1.85 (1.8449 +/- 0.0013) eV for BFO nanocrystallites supporting their potential application as visible light-response photocatalysts. Direct bandgap value obtained from reflectance measurement is determined to be 2.25 (2.2464 +/- 0.0065) eV.