Structural, Thermal, and Optical Properties of GeO₂-La₂O₃-TiO₂ Glasses

Abstract

La2O3-TiO2 glasses show promising application prospect in fields of lenses, optical windows, and optical communication, owing to high refractive index and excellent performance. However, this glass cannot be prepared into large size because of its weak glass forming ability. This seriously limits the application of this new glass. In this study, introducing the network former GeO2, the glass forming ability can be effectively improved. This enables large-sized GeO2-La2O3-TiO2 (GLT) glass to be prepared using conventional methods. Differential thermal analysis shows that GLT glasses have high glass transition temperature and strong resistance to precipitation, with Tg and ΔT (ΔT =Tc-onset-Tg) greater than 833 and 209 ℃, respectively. The refractive index is up to 2.06. The transmittance can reach 78% in the visible and near-infrared wavelength bands. The influence of titanium contents on the structure, thermal, and optical property has been researched. The results show that the glass forming ability and thermal stability can be weakened by increasing the content of TiO2. The molar volume and oxygen electron polarizability exhibit the same variation trends as the refractive index of the samples. This glass is important for developing new devices with high performance, light weight, and small size.