溶胶-凝胶制备ZnTiO3粉体及其表征

以钛酸丁酯、硝酸锌、乙醇和乙酸为原料，采用溶胶-凝胶工艺制备了纯净六方ZnTiO₃粉体.利用TG-DTA、XRD和FE-SEM等检测手段对前驱体凝胶的热分解、相变以及粉体结构和形貌进行研究.结果表明:ZnTiO₃凝胶前驱体热分解分3个阶段，第1阶段在262 ℃以下主要为有机物的分解过程；第2阶段为262~700 ℃，此时的粉体为非晶态立方相ZnTiO₃；六方ZnTiO₃相的生成发生在第3阶段700~900 ℃.获得纯净六方ZnTiO₃相的较为合适的工艺条件为:前驱体在60 ℃进行溶胶，然后在700~900 ℃煅烧2 h. 

Characterization of ZnTiO3 powders prepared by sol-gel process

The pure hexagonal ZnTiO₃ powders were prepared by sol-gel process using tetrabutyl titanate (Ti (OC₄H₉)₄), zinc nitrate hexahydrate (Zn (NO₃)₂·6H₂O), anhydrous ethanol (CH₃CH₂OH) and glacial acetic (CH₃COOH) as the raw materials. The thermal behavior and phase transformation of the precursor xerogel were investigated by thermogravimetry and differential thermal analysis (TG-DTA) and X-ray diffraction (XRD). The crystalline phase, morphology and grain size of the powders were characterized by XRD and field emission scanning electron microscope (FE-SEM). The thermal behavior of precursor xerogel was divided into three stages in the TG-DTA analysis. The first stage was below 262 ℃ with the decomposed organic solvents. Amorphous cubic ZnTiO₃ was obtained at the second stage at about 262~700 ℃, and hexagonal ZnTiO₃ appeared at the last stage, i.e.700~900 ℃. The purity hexagonal ZnTiO₃ powders can be prepared by heat treatment at 700~900 ℃ for 2 h of the precursor xerogel, which was obtained by the sol reaction at 60 ℃.