溶胶凝胶法制备的钛酸钡铁电微晶玻璃的显微结构与介电特性

MICROSTRUCTURE AND DIELECTRIC PROPERTIES OF BARIUM TITANATE GLASS-CERAMICS PREPARED BY THE SOL-GEL METHOD

通过对钛酸钡铁电微晶玻璃的体系选择和成分设计,利用溶胶凝胶法合成了具有纯钛酸钡结晶相的微晶玻璃。研究了合成过程中凝胶结构变化和析晶行为。结果表明:纯钛酸钡铁电晶体可以在BaO TiO2Al2O3SiO2凝胶中通过调整热处理条件而控制析晶,钛酸钡晶体的析晶活化能为657 kJ/mol。通过控制玻璃体中钛酸钡晶粒的尺寸,利用Raman光谱研究了其铁电本征尺寸效应。结果表明:钛酸钡晶体在玻璃体中的铁电临界尺寸为19 nm。

Through selecting synthesis systems and designing chemical composition, a glass-ceramics contained pure barium titanate crystallites was prepared by the sol - gel method. The structural change and crystallization behavior of BaO-TiO2- Al2O3- SiO2 gel were investigated. The results show that pure BaTiO3, crystallites can be derived from BaO-TiO3-Al2O3-SiO2 gel by controlling the heat treatment conditions. Activation energy of crystal growth for BaTiO3, is about 657 kJ/mol. Through controlling the crystal size of barium titanate in the glass-ceramics, the intrinsic size effect of barium titanate in the glass matrix was investigated by the Raman spectrum technique. The results show that the BaTiO3, critical size for ferroelectric transition in the glass matrix is about 19 nm.