Hydrothermal synthesis of potassium niobate powders

Potassium niobate (KNbO3) powders with the orthorhombic structure were successfully synthesized through the hydrothermal reaction of Nb2O5 and KOH at 200 °C. The concentration of KOH had a great effect on the morphology and particle size of KNbO3 powders. The morphology of KNbO3 powders changed from rod-like to cubic particles when the potassium hydroxide (KOH) concentrations was in the range of 6.25–15 M. Particularly, when the KOH concentration was 7.5 M and the amount of Nb2O5 was 0.02 mol, dodecahedral crystalline was found in the precipitations.