Multicomponent Glasses of GeO2 and Sb2O3 with Bi2O3, T12O, andlor PbO

Previous studies on glass formation involving GeO₂ with Bi₂O₃, TI₂O, and PbO were extended by the use of Sb₂O₃. Wide areas of glass formation occur in the systems GeO₂-PbO-Sb₂O₃ and GeO₂-Bi₂O₃-Sb₂O₃ at all but the lowest GeO₂ contents; the region of single-phase glasses in the system GeO₂-Tl₂O-Sb₂O₃ is severely restricted. 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; these properties are presented in diagrams for the GeO₂-Sb₂O₃ binary and for two ternary systems. Based on calculated values of Δ_o,the waveleneth for zero material dispersion. and dM/dΔ . the material disiersion slope at Δ_o, compositions in these systems may be useful for the construction of ultralow-loss optical waveguides in the 3 to 4 μm region.