Chapter 13: Germanate Glasses Containing Nb₂O₅ or Ta₂O₅ Check Access

Glasses containing Nb₂O₅ or Ta₂O₅ are of interest for application in optical devices. Although there are no reports of formation of binary germanate glasses containing either Nb₂O₅ or Ta₂O₅, ternary glasses containing alkali oxides are readily formed over large compositional regions. The density and glass transformation temperature of the glasses containing Nb₂O₅ exhibit the anomalies found for alkali germanate glasses, while the glasses containing Ta₂O₅ do not exhibit any anomalies. Niobium oxide has little, if any, effect on the electrical conductivity of the alkali niobium germanate glasses. A small amount of data is available for the density, refractive index, glass transformation temperature, and shear modulus of lanthanum tantalum germanate glasses containing constant concentrations of La₂O₃.