Bismuth titanate (Bi₄Ti₃O₁₂) is a suitable material for applications as high temperature transducers, capacitors and sensors, due to its high Curie temperature and high piezoelectric coefficient. However, its layered structure and low crystal symmetry leads to difficulty in polarizing the conventional polycrystalline Bi₄Ti₃O₁₂ ceramics. It is desirable to obtain Bi₄Ti₃O₁₂ ceramics with textured microstructure since improved properties can be achievied in textured ceramics comparing to ceramics with randomly oriented grain structure. Bi₄Ti₃O₁₂ particles with plate-like morphology are preffered templates for fabricating textured Bi₄Ti₃O₁₂ ceramics. Molten salt synthesis (MSS) is a suitable method for synthesizing oxide powders with anisotropic particle morphologies.

Bi₄Ti₃O₁₂ platelets were obtained by MSS method in NaCl-KCl and Na₂SO₄-K₂SO₄ fluxes, using a mechanicaly mixed Bi₂O₃-TiO₂ mixture as the starting material. The mixtures of the precursors and salts were placed in a sealed alumina crucibles and heated at temperatures ranging from 700 to 1100ºC for a desired time period. The effects of the synthesizing temperature and time, salt species and salt content on the formation process and morphology of the Bi₄Ti₃O₁₂ plateletes were investigated. The morphology of the powders obtained was examined by SEM. Phases present and their crystal structures were determined by XRD.

In both fluxes, aggregate particles were formed during the initial period of reaction between Bi₂O₃ and TiO₂. The shape of the particles in the aggregate changed from lumpy to plate-like, and finally discrete plate-like particles were formed, on heating for longer periods or at higher temperatures. Plate-like Bi₄Ti₃O₁₂ particles with an average diameter of 5 μm and thickness <0,5 μm were obtained. The plate face was perpendicular to the crystallographic c-axis. The powders obtained during the formation process have imperfections of ionic configuration along the c-axis, which is eliminated during the growth.

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