Synthesis of high aspect ratio platelike Ba_1-xCa _xTiO₃ particles by topochemical microcrystal conversion method

A-site complex perovskite Ba_1-xCa_xTiO₃ (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 Bi ₄Ti₃O₁₂ and the powdered BaCO ₃-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 Ca ²⁺ 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 Ba_1-xCa_xTiO ₃ particles was inherited from that of the precursor phase Bi ₄Ti₃O₁₂. 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.