Synthesis and properties of high aspect ratio SrBi₄Ti ₄O₁₅ microplatelets

(001) oriented SrBi₄Ti₄O₁₅ (SBT) microplatelets with Aurivillius-type crystal structure were fabricated by molten salt synthesis. The effects of flux type selection and salt-to-oxide ratio variation on crystallization habit and morphology of the product were investigated. The sodium salt fluxes facilitate the formation of Sr ₂Bi₄Ti₅O₁₈ large size platelets (≤17 μm in length), while potassium salt fluxes create favorable condition for the growth of small size SrBi₄Ti₄O₁₅ platelets (≤5 μ m in length). When using KCl flux, a higher salt-to-oxide ratio is beneficial to produce smaller SBT platelets with relatively narrow size distribution. The ferroelectricity and piezoelectricity of an individual SBT platelet were examined by piezoelectric force microscopy. These microcrystals are suitable template candidate to achieve highly textured ceramics for high temperature applications.