Synthesis of high aspect ratio platelike Ba1−xCaxTiO3 particles by topochemical microcrystal conversion method

A-site complex perovskite Ba1−xCaxTiO3 (x≤0.25) platelike particles with high aspect ratio (edge length to thickness) of 8–10 and micron sizes (6–8 μm) were synthesized via a topochemical microcrystal conversion reaction between the platelet Bi4Ti3O12 and the powdered BaCO3–CaCO3 mixture at 950 °C in KCl flux. The morphology and A-site elemental composition of the resulting particles has been studied with reference to the effect of the concentration and molar ratio of the Ca2+ and Ba2+ in molten salt. The A-site elemental composition of the resultant particles was correspond linearly to the molar ratio of the Ca2+ and Ba2+ in molten salt. The morphology and size distribution of the synthetic Ba1−xCaxTiO3 particles was inherited from that of the precursor phase Bi4Ti3O12. The designed synthesis routine has potential to synthesize other A-site complex perovskite platelike particles with high aspect ratio and micron sizes, which serving as a suitable template and seeded crystals can be employed to produce highly textured ceramics via TGG/RTGG method and single crystals by SPC technique.