KNbO_3粉体的低温合成研究

PREPARATION OF KNbO_3 POWDERS AT LOW TEMPERATURES

以尿素为燃烧剂,采用低温燃烧法在较低的温度下合成了纯相的KNbO3粉体。采用XRD、SEM和TG-DSC研究了KN晶相的形成过程。结果表明,采用该法可在550℃下合成纯相的KN粉体,当煅烧温度升高至700℃时,立方相的KN粉体转变成了正交相的KN粉体。本研究还就工艺参数对粉体物相的影响进行了讨论。

Pure KNbO3 powder was prepared at low temperature by a combustion method using K2CO3 and Nb2O5 as raw materials and urea as fuel.The crystal structure and morphology of the powder were characterized by X-ray diffraction and scanning electron microscope.The results reveal that cubic phase KNbO3 powders can be obtained at 550℃ by the method and with the temperature increasing to 700℃ they change into the orthorhombic phase.The synthesis parameters are studied to reveal the optimized synthesis conditions for preparing pure KNbO3 powders.