Topochemical Synthesis of a High‐Aspect‐Ratio Platelet NaNbO ₃ Template

Abstract

A high‐aspect‐ratio platelet sodium niobate (NaNbO 3 ) was synthesized by a topochemical reaction. Plate‐like layered‐perovskite Bi 2.5 Na 3.5 Nb 5 O 18 (BNN5) as a precursor was first prepared, and then Bi 3+ in the precursor phase was replaced by Na + through topotactic conversion and perovskite NaNbO 3 formed at 950°C in NaCl molten salt. NaNbO 3 crystals had an average length of 15 μm and a thickness of 0.5 μm. Scanning electron microscope and high‐resolution transmission electron microscope analyses indicated that the retro‐synthesis process of the desired perovskite NaNbO 3 retained the morphological and structural features of the BNN5 precursor. It may be possible to synthesize other perovskite‐structured templates using the same method.