Synthesis and properties of high aspect ratio SrBi4Ti4O15 microplatelets

• Unique SBT microplatelets with tailored particle sizes can be fabricated by MSS.
• Only potassium fluxes create favorable condition to grow pure SBT platelets.
• Higher salt amount is beneficial to produce uniform platelets with smaller sizes.
• SS-PFM shows ferroelectricity and piezoelectricity of an individual SBT platelet.

(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 Sr2Bi4Ti5O18 large size platelets (≥17 µm in length), while potassium salt fluxes create favorable condition for the growth of small size SrBi4Ti4O15 platelets (≤5 µm 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.