BiFeO_3 Powder Rapid Synthesized by Molten Salt Method

BiFeO3 powders were rapidly synthesized by the molten salt method using Bi2O3 and Fe2O3 as raw materials,NaNO3 and KNO3 as complex molten salt. These effects of molten salt temperature,molten salt ratio,hold time and cooling rate on the phase evolution of BiFeO3 powders had been investigated.And the formation process of BiFeO3 was also discussed during the synthesis by the molten salt method.When the molten salt temperature was 500 ℃,Bi25FeO40 phase was formed throught the reaction of Bi2O3 and Fe2O3. A small amount of BiFeO3 was formed with the molten temperature increasing to 600 ℃.Almost pure BiFeO3 phase was obtained when the molten salt temperature further increased to 650 ℃ and 700 ℃. A trace Bi25FeO40 and Bi2Fe4O9 phase were still observed in the powders. Decomposition of BiFeO3 phase was suppressed by quenching. It was found that almost pure BiFeO3 phase in the quenched powders was synthesized at 700 ℃ for 10 min with the molten ratio of 5∶1.