Glycothermal preparation of potassium niobate ceramic particles under supercritical conditions

Abstract

Potassium niobate KNbO 3 particles were synthesized via a newly developed glycothermal process using isopropanol as the reaction medium in supercritical environment. Increasing the concentration of KOH and the molar ratio of K +/Nb 5+ substantially facilitated the formation of KNbO 3. When the concentration was 0. 5 M and the molar ratio of K +/Nb 5+ was greater than 2:1, well crystallized monophasic KNbO 3 was successfully produced at as low as 250 °C. In comparison with the traditional hydrothermal process, the supercritical glycothermal process greatly reduced the required concentration of KOH. This supercritical glycothermal process provides a new prospective approach for synthesizing electronic ceramic powders at low temperatures.