(中南大学 材料科学与工程学院， 长沙 410083)
摘 要: 以硝酸氧锆、 钛酸四丁酯、 醋酸铅为原料， 乙二醇为溶剂， 用溶胶-凝胶技术制备了钙钛矿型的锆钛酸铅（PZT）纳米晶。 实验中发现前驱物间的聚合反应使硝酸氧锆能很好地溶于乙二醇。 通过对原料、 不同温度下的溶胶、 干凝胶、 PZT粉末的红外光谱分析， 给出了溶胶、 凝胶形成的机理， 进一步证实溶胶-凝胶过程中通过前驱物的水解、缩聚反应形成金属元素与乙二醇相配位的链状或网状聚合物。 原料中所含的NO3-离子反应后形成的硝酸酯被包裹在溶胶和凝胶的聚合物网络中， CH3COO－离子反应后生成醋酸酯并通过两个O与聚合物网络中的金属元素配位。
关键字: PZT； 溶胶-凝胶法； 红外光谱； 反应机理
（School of Materials Science and Engineering, Central South University,
Changsha 410083, China）
Abstract:PZT nano-crystalline powders were prepared by sol-gel process. Zirconium oxynitrate, tetrabutyl titanate and lead acetate were used as raw materials and ethylene glycol as solvent. It is found that the solubility of zirconium oxynitrate in ethylene glycol is greatly improved due to the polycondensation of the precursors. The IR analysis of raw materials, the sol under different temparetures, the dried gel and the PZT powder were used to study the reaction mechanism and to identify the possible polymer structures developed during synthesis of the solutions. The results show that polycondensation process, which proceeds simultaneously with the synthesis reaction, leads to the formation of bonds between the diol and the metal ions, zirconium, lead or titanium, and the inorganic polymer network are obtained by the process. The anions of NO3-and CH3COO－ are changed into esters respectively, the former are packed in the gel network, and the latter chelate with metal elements in polymers.
Key words: PZT； sol-gel process； IR; reaction mechanism
