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 °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 °C. BiFeO3 powder calcined at 600 °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 × 10−3 emu g−1 and a coercive field value (Hc) nearly 500 Oe. The UV–visible spectra showed maximum adsorption at ∼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.