Fabrication of Plate-like Sr₃Ti₂O₇ Particles using Molten Salt Synthesis

Plate-like Sr₃Ti₂O₇ powders with anisotropy were prepared by KCl molten salt synthesis (MSS) method, the effect of different SrCO₃TiO₂ ratio and calcination condition on the phase transition, particle size and morphology of powders were investigated. The results show that SrTiO₃phase coexist with Sr₃Ti₂O₇ phase and SrTiO₃ is the main phase as the SrCO₃/TiO₃ ratio is 1.15-1.25:1. Pure Sr₃Ti₂O₇ phase can be obtained as the SrCO₃/TiO₂ ratio is 1.55-1.65:1. The aspect ratio of plate-like particles increases firstly and then decreases as the SrCO₃/TiO₂ ratio increases. The sealed and unsealed condition has no influence on the phase structure of the powders. But the aspect ratio of unsealed particles is smaller than that of sealed particle. Finally, the formation mechanism for Sr₃Ti₂O₇ particles was discussed.