钡钛酸盐玻璃的形成、性质和结构

本文目的在于研制高二氧化钛含量玻璃。当二氧化钛与氧化钡含量达80%时(其中TiO_2含量为30—60%),可以形成稳定的玻璃。这种玻璃具有高折射率(~nD>2.1)与良好的化学稳定性。文中还对高钛玻璃的着色进行了研究,认为主要由于熔制过程中失氧所引起。因此,可以通过熔制条件的控制、热处理等途径大大减轻玻璃的着色,从而能提高玻璃的反射率。通过红外光谱与X-射线谱对玻璃中的Ti~(4 )离子的配位状态作了分析,证明Ti~(4 )离子处于TiO_(?)]状态。电镜观察确定,高钛酸盐玻璃在T_g以上一定温度热处理时,首先产生分相,然后体积晶化。对所析出的晶相也进行了研究,证实一般由钛酸钡为主的钛酸盐所组成。根据研究结果,提出了钡钛酸盐玻璃的结构示意图。

Formation, properties and structure of barium titanate glasses

The aim of this study was to produce high TiO_2 content (30-60wt%)glasses. Stable titanate glasses with high content of TiO_2 and BaO could be obtained even without the other glass-forming oxides. The synthesized glasses had high refractive index(n_D>2.1) and good chemical durability. It has been demonstrated that the coloration of titanate glasses with high TiO_2 content is due to the oxygen losses during the melting process. A systematic controlling of melting process and heat treatment has led to the successful decoloration of high TiO_2 containing glasses. At the same time the reflectance increased. Infrared and X-ray diffraction spectra showed that Ti~(4 ) in titanate glasses is in sixfold coordination.The crystallization of titanate glasses is generally preceded by the phase separation. By electron microscopy the phase separation of the titanate glasses was observed to take place during the heat treatment at the temperature above T_g. The resulted crystalline phases are mainly different titanates. Based upon the vibrational spectra, a schematic model of structure of titanate glasses is proposed.