中文摘要：

以Nb2O5和NaOH为原料，KOH为矿化剂，在200℃，浓度为1mol／L或2．5mol／L的碱性溶液中用水热法制备了具有正交晶系结构的NaNbO3粉体．采用XRD和FTIR对产物结构进行了表征，用SEM观察了粉体的结晶形貌，用EPMA方法估算了产物的主要化学成分．研究了KOH、表面活性剂以及反应时间等工艺条件对产物形貌和晶体结构的影响．结果表明，在相同温度下，OH^-的摩尔浓度及反应时间是影响产物结构和形貌的关键因素．利用透射电镜（TEM）和电子衍射（EDS）发现合成的NaNbO3晶粒中存在超结构．

英文摘要：

The hydrothermal synthesis of sodium niobate （NaNbO3） powders with orthorhombic structure using Nb2O5 and NaOH as raw materials, KOH as mineralizer, was investigated. The powders were identified by X-ray powder diffraction （XRD） and the Fourier transform infrared （FTIR）. The microstructural evolution and the particle size of the samples were examined by scanning electron microscope （SEM）, and the main chemical compositions of the powders were studied by EPMA. It is found that there is super-structure existing in NaNbO3 powders by TEM and EDS analysis. The experimental results show that the alkaline concentration and reaction time have influences on the crystal structure and morphology of the resultant powders.