Low-temperature synthesis of BiFeO3 nanopowders via a sol–gel method

Bismuth ferrite (BiFeO3) nanopowders were synthesized by a sol–gel method at the temperature as low as 450 °C. The obtained sol was transparent and homogenous when the mixture ionic concentration was properly controlled with the help of ethylene alcohol. The preparation process of crystalline BiFeO3 could be divided into three stages: (i) the evaporation of organics and decomposition of nitrogen-containing organics below 200 °C; (ii) the collapse of Bi–Fe gel network in the temperature range of 200–300 °C and (iii) the formation of BiFeO3 nanopowders by the solid-state reaction between Bi2CO3O2 and Fe2O3.