East China Institute of Chemical Technology, Shanghai 201107, PRC
Abstract:
The formation of high titanium oxide (30–60 wt%) containing glasses was studied. Stable titanate glasses with high content of TiO2 and BaO could be obtained even without other glass-forming oxides. It is demonstrated that the coloration of titanate glasses with high content of TiO2 is due to oxygen loss during the melting. A systematic study of controlling melting and heat treatment conditions led to the successful decoloration of titanium oxide containing glasses. Infrared spectra and X-ray diffraction studies showed that Ti4+ in titanate glasses is in sixfold coordination. Phase separation was observed by electron microscopy when the titanate glasses were heat-treated at the temperature above Tg. The crystallization of titanate glasses is generally preceded by phase separation. The obtained crystalline phases are mainly different titanates.