Synthesis of SrBi2Ta2O9 nanocrystalline powder by a modified sol–gel process using bismuth subnitrate as bismuth source

Steady sol and gel of SrBi2Ta2O9 (SBT) was prepared using pentaethoxy tantalum, strontium acetate, and bismuth subnitrate as raw materials and ethylene glycol as a solvent. After a dried gel was pretreated at 350 °C for 30 min and then it was calcined at 800 °C for 1 h, the perovskite phase SBT ferroelectric powder was obtained. The formation mechanism of the sol and gel was proposed. In the baking process perovskite phase SBT forms via a reaction between bismuth oxide (cubic phase) and strontium tantalate (orthorhombic phase).