Synthesis of Potassium Niobate by Rotary-Hydrothermal Process and Microstructural Evaluation

Abstract

This study deals with the development of the novel rotary-hydrothermal process for potassium niobate, in special monophase KNbO₃, under mild hydrothermal conditions at lower synthetic temperatures for short synthetic time with using lower concentration of KOH solution. Potassium niobates were synthesized by the conventional hydrothermal process and novel rotary-hydrothermal process and the products were characterized by XRD and SEM observations. As a result, monophase KNbO₃ was obtained at 180°C for 12h with using 7.5 M KOH solution by the rotary-hydrothermal process and the particle size for their monophase KNbO₃ products was finer than one synthesized by the conventional hydrothermal process. Effect of rotary-hydrothermal process on the microstructure and morphologies for potassium niobate was discussed, compared to the conventional hydrothermal process.