Synthesis and formation mechanisms of high aspect ratio KNb ₅Bi₂O₁₆ template via topochemical method

Plate-like Bi₅Nb₃O₁₅ (B5N3) particles and rectangular KNb₅Bi₂O₁₆ (KN5B2) particles were synthesized by the molten salt process and topochemical microcrystal conversion (TMC), respectively. The effects of the synthesis parameters on the phase structure and morphology of B5N3 precursor and KN5B2 were investigated. Results indicated that the retro-synthesis process of the as-synthesized KN5B2 retained the morphology and structural feature of the B5N3 precursor. The prepared KN5B2 particles with high aspect ratio of 20-30 are promising templates for texturing bismuth-layer and alkali niobate based ceramics by (reactive) templated grain growth method. The same method can be applied to other perovskite-structured templates.