Direct synthesis of platelet KNbO3 particles using KNb3O8 precursor and KNO3 self-flux

Platelet KNbO3 particles having perovskite single phase have been successfully synthesized by a new simple procedure based on the dry-mixing technique and self-flux method using KNO3 source that required no washing and filtration process. Well-crystalline edge-shaped platelet KNb3O8 particles were first obtained by the reaction between KNO3 and Nb2O5. Next, they were reacted with second KNO3 to form platelet KNbO3 particles by the topochemical conversion method. The platelet KNbO3 particles synthesized at 800°C demonstrated a relatively high aspect ratio of around 5 with edge lengths of about 2–10 and 10–40 µm in size for the tabular and thickness directions, respectively. The topochemical conversion mechanism from KNb3O8 to KNbO3 was also proposed in this study.