Synthesis of Pure Phase Bi۲Fe۴O۹ Submicron Particles via Chemical Co-Precipitation Method

Ternary bismuth ferrites (perovskite BiFeO۳, Mullite Bi۲Fe۴O۹, and Bi۲۵FeO۴۰ with Sillenitecrystal structure) are important functional materials due to their applications in the field ofmemories, sensors and catalysts in various forms such as single crystal, thin film, nano particle.Bi۲Fe۴O۹ (BFO) shows at room temperature a crystallographic structure with orthorhombicsymmetry, which belongs to the space group Pbam, No. ۵۵. Several procedures such ashydrothermal process, sol–gel (for example: EDTA route, glycerin method and PVA process)and solid-state reaction have been developed to synthesize single-phase BFO. No work hasbeen reported concerning the synthesis of Bi۲Fe۴O۹ via chemical co-precipitation. BFOnanoparticles were successfully synthesized by chemical co-precipitation method at roomtemperature. The pH value in this experiment was fixed on ۸, ۱۰ and ۱۲. The as-preparedpowders, characterized by X-ray diffraction (XRD), field emission scanning electronmicroscope (FESEM) and vibration sample magnetometer (VSM). Kinetic of reactions increasewith increasing pH value and result in non-homogeneity in precipitate that causes impurities.Cubic shape of particles indicates pure phase formation of Bi۲Fe۴O۹. The size of crystalliteswas ۱۲۰ nm calculated from Scherer equation. The magnetic hysteresis loop shows the antiferromagnetism(AF) ordering in synthesized BFO.

Keywords:

Bi۲Fe۴O۹ , Co-precipitation , Electroceramic , Synthesis.