溶胶-沉淀法制备钛酸锶钡粉末及其水热处理

Hydrothermal treatment of barium strontium titanate （BST） powders obtained by solution-precipitation method

摘要: 通过溶胶-沉淀法制备出完全钙钛矿结构的Ba_0.71Sr_0.29TiO₃(BST)粉末,粉末的颗粒尺寸约为300nm。但得到的BST粉末不稳定,在乙酸中容易分解。通过TG-DTA和XRD分析,直接沉淀得到的粉末颗粒失重大,而且由于颗粒所吸附的有机物阻碍了Ba²⁺和Sr²⁺的扩散,造成了直接沉淀的BST颗粒内部的组分不均匀和结晶不完全。通过对直接沉淀的BST粉末进行150-200℃的水热后处理,其结晶性得到了很大的改善,稳定性也得到了提高。实验表明,水热处理具有与烧结相似的效果,但BST粉末的分散性得到了改善。

Abstract: Barium strontium titanate （Ba_0.71Sr_0.29TiO₃） powders were prepared by solution-precipitation method. The BST powders are single perovskite phase with particle size of about 300 nm. The newly precipitated powders are instable and poorly crystallized. TG-DTA analysis proves that the BST powders have a loose structure due to absorbed organic compounds, which also cause the inhomo-geneity in a single particle. Hydrothermal treatments at 150-200 ℃were conducted for the BSTpowders, and the hydrothermally treated BST powders have better crystallization and smaller weight loss.