【作者】 左海英；

【导师】 郝素娥；

【作者基本信息】 哈尔滨工业大学 ， 无机化学， 2006， 硕士

【摘要】 本文分别采用溶胶-凝胶法和沉淀法制备了ZnO粉体，确定了粉体制备的工艺条件；对ZnO粉体进行了La、Pr气相扩渗，制备了新型ZnO导电粉；对稀土气相扩渗后ZnO粉体的组成、结构和导电性能的变化进行了研究。 溶胶-凝胶法制备ZnO粉体的工艺条件：室温，搅拌3h，煅烧温度840℃，烧结制度为200℃保温1h，400℃保温2h，840℃保温1h。沉淀法制备ZnO粉体的工艺条件：分步洗涤，滴速80滴／min，煅烧温度200℃。与溶胶-凝胶法相比，沉淀法制备出的ZnO粉体粒度分布均匀，粒径较小，在100nm左右。 对所制备的纳米ZnO粉体进行了La、Pr气相扩渗，实验结果表明，La、Pr扩渗能明显改善ZnO粉体的导电性能。当La的扩渗浓度为2％（wt），扩渗时间为4h，扩渗温度为420℃时，改性ZnO的室温电阻率最低，由扩渗前的10¹⁴Ω·cm下降到1.6×10⁶Ω·cm；当Pr的扩渗浓度为2％（wt），扩渗时间为4h，扩渗温度为400℃时，改性ZnO的室温电阻率最低，由扩渗前的10¹⁴Ω·cm下降到1.9×10⁶Ω·cm。 XRD测试表明，经过La、Pr气相扩渗，ZnO粉体的主体特征峰没有明显变化，但分别在29.5°和30.5°出现了与稀土有关的特征峰，说明La、Pr渗入了ZnO粉体，并导致了ZnO粉体导电性的提高。SEM测试表明ZnO粉体经稀土La、Pr扩渗后晶粒明显细化，团聚现象减弱。热重分析表明La扩渗后的ZnO粉体具有较好的热稳定性，有良好的应用前景。更多还原

【Abstract】 ZnO powders were prepared by sol-gel method and precipitation method. The preparation parameters for ZnO powders were studied. ZnO conductive powders were penetrated by gaseous penetration of La and Pr in gaseous state. The composition, structure and electric conductivity of ZnO powders were studied.The preparation parameters of ZnO powders by sol-gel method: room temperature, stirring 3h, sintering at 840°C, sintering 1h at 200°C, 2h at 400°C, and 1h at 400°C. The process parameters of precipitation method are: sequential washing, 80 drops/min, sintering at 200°C. ZnO powders prepared by precipitation method are uniform. The grain size is about 100nm, which is smaller than that of ZnO powders prepared by sol-gel method.ZnO conductive powders were prepared by gaseous penetration of La and Pr in gaseous state. Experiment results show that La and Pr can evidently improve the electric conductivity of ZnO powders. When the La content is 2%（wt）, the penetration time is 4h, the penetration temperature is 420°C, the resistivity of modified ZnO powders is lowest, which decreased from 10¹⁴Ω·cm to 1.6×10⁶Ω·cm. When the Pr content is 2%（wt）, the penetration time is 4h, the penetration temperature is 400°C, the resistivity of modified ZnO powders is lowest, which decreased from 10¹⁴Ω·cm to 1.9×10⁶Ω·cm.XRD analysis show that, after gaseous penetration of La and Pr in gaseous state, the main peaks of ZnO powders did not change, but there are two small peaks at 29.5° and 30.5°, which are relating to La and Pr. It indicated that La and Pr have penetrated into ZnO powders and leaded to the increase in electric conductivity. SEM results show that, after gaseous penetration, grains of the powders are refined evidently and agglomeration behavior is decreased. Thermogravimetric analysis show that ZnO powders penetrated by La has good thermal stability, which has a good application in the future.更多还原