水热法制备钛酸铋钠粉体及其生长机理研究

Synthesis and Growth Mechanism of Na_(0. 5)Bi_(0. 5)TiO_3 Powder through Hydrothermal Method

以钛酸四丁酯Ti（OC4H9）4和五水硝酸铋Bi（NO3）3·5H2O为原料，NaOH为矿化剂，通过水热法制备钛酸铋钠（Na0.5Bi0.5TiO3）粉体。通过X射线衍射仪（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）对反应制备的粉体进行物相分析。结果表明，反应温度、反应时间及矿化剂浓度均是影响钛酸铋钠粉体制备的关键因素。利用JMA方程对其进行动力学计算分析，结果表明，在反应温度为120—180℃时，NBT颗粒的Avrami指数n随温度的升高而减小，而反应速率k则相反，反应活化能Ea为50．14kJ·mol^-1。

Na0.5Bi0.5TiO3 （NBT） powders were successfully prepared by the hydrothermal method using Ti （OC4H9） 4 and Bi（NO3）3·5H2O as raw materials, NaOH as mineralizer. The phase composition and particle morphology of the as-prepared powders were characterized by X-ray diffraction （ XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The reaction temperature, reaction time and the concentration of NaOH were the key points to synthesize NBT powders. The growth kinetics of NBT was evaluated by the JMA equation. The results showed that when the temperature was in the range from 120℃ to 180℃, the Avrami exponent n decreased and the reaction rate k increased as temperature rose. The activation energy of NBT was 50.14 kJ · mol^-1.