Glass-Forming Systems Involving GeO2 with Bi2O3, Ti2O, and PbO

The previously studied system GeO₂-Bi₂O₃-TI₂O was extended with the addition of PbO using air- and water-quenched melted samples. Large areas of glass formation were found in the systems GeO₂–Bi₂O₃–PbO and GeO₂–PbO–Tl₂O at all but the lowest GeO₂ contents. Glasses were examined by powder X-ray diffraction, differential thermal analysis, thermomechanical analysis, and Archimedes'technique to obtain glass transition and crystallization exotherm temperatures, thermal expansion coefficients, and densities, which are presented in diagrams for the GeO₂-PbO binary and for the two ternary systems. Based on calculated values of λ₀, the wavelength for zero material dispersion, compositions in this system may be useful for construction of ultralow-loss optical waveguides in the μm region.