Synthesis of BiFeO۳ nanoparticles by the reverse chemical co-precipitationmethod: Influence of pH and study of the reaction mechanism

The reverse co-precipitation method was used for synthesis of the pure phasemultiferroic BiFeO۳ (BFO) nanoparticles. Influence of different pH value on the purity ofbismuth ferrite powders was investigated. Thermogravimetric-differential thermal analysis (TGDTA)technique indicated that the optimal temperature for calcination is ۵۵۰°C. Atomic ratio ofBi to Fe is approximately ۱:۱ for BiFeO۳ powders, as determined by energy dispersivespectroscopy (EDS). The phase formation and the existence of transient phases (like Bi۲۵FeO۳۹and Bi۲Fe۴O۹) has been studied using X-ray diffractometry (XRD). The morphological features ofthe nanopowders were characterized by field emission scanning electron microscopy (FESEM).The magnetic properties of the synthesized powders were measured using vibrating samplemagnetometery (VSM). The results showed that the BFO powders have R۳c crystal structure.The FESEM micrographs showed pseudo-cubic shape and particles size in the range of ۲۵-۲۳۴nm. The magnetic hysteresis loops were indicated a weak ferromagnetic behavior of the samplesat room temperature.

Keywords:

Reverse co-precipitation , Bismuth ferrite , Magnetic properties