Synthesis and dielectric properties of BiFeO3 derived from molten salt method

BiFeO₃ powder was synthesized in NaCl media at temperature range from 700 to 800 °C, using Bi₂O₃ and Fe₂O₃ as raw materials. Effects of calcining temperature and salt ratios on the synthesis of BiFeO₃ powder had been investigated. It was found that NaCl effectively promoted the formation of BiFeO₃. Almost pure BiFeO₃ phase with a very small amount of Bi₂Fe₄O₉ phase was synthesized at 750 °C with salt weight ratios of 1:1. A large amount of BiFeO₃ phase decomposed to Bi₂Fe₄O₉ and Bi₂₅FeO₃₉ phase when the temperature was up to 800 °C. In the present method, the calcining temperature played an important role in the formation of BiFeO₃ phase. BiFeO₃ ceramics derived from molten salt method were prepared and exhibited the higher dielectric constant.