Preparation of cubic Na_0.5Sr_0.25NbO₃ particles by molten salt synthesis

Pure Na_0.5Sr_0.25NbO₃ particles were successfully synthesized using the molten salt synthesis method in the SrCO₃+Nb₂O₅+KCl+NaCl system, which could not be obtained in the SrCO₃+Nb₂O₅+NaCl system. The result suggested that the fabrication process of Na_0.5Sr_0.25NbO₃ was different for the two systems. In the SrCO₃+Nb₂O₅+NaCl system, NaSr₂Nb₅O₁₅ formed and then converted into Na_0.5Sr_0.25NbO₃. In the SrCO₃+Nb₂O₅+KCl+NaCl system, Na_0.5Sr_0.25NbO₃ could be obtained directly by the reaction between the intermediate KSN and NaCl. The effects of the NaCl salt content and heated temperature on the purity and size of particles were investigated. Pure Na_0.5Sr_0.25NbO₃ powder crystals with uniform particle size could be prepared at the heated temperature of 1,200 °C and NaCl salt-to-oxide ratio of 2, which were ideal raw material for preparing Na_0.5Sr_0.25NbO₃ ceramics.