Abstract

The infrared (IR) spectra of (100-x)TeO2–xWO3 glasses reveal that the glass network consists of [TeO3]/[TeO3+1], [TeO4], [WO4], and [WO6] groups as basic structural units. Addition of WO3 oxide to the binary TeO2–WO3 glasses increases the amount of lower coordination of [TeO3]/[TeO3+1] units and decreases the higher coordination of [TeO4] units and also the formation of Te–O–W linkages at the expense of Te–O–Te linkages. The IR spectra of 60TeO2–(40-x)WO3–xPbO glasses reveal that the glass network consists of [TeO3], [TeO4], [WO4], [WO6], and [PbO4] units. Changes in the coordination state of tellurium and tungsten ions occur when the PbO and WO3 concentrations are varied. The dual role of the lead ions is confirmed in 60TeO2–(40-x)WO3–xPbO glass system. The W ion coordination state changes from 4 to 6 when WO3 concentration increases beyond 30 mol% in both (100-x)TeO2–xWO3 and 60TeO2–(40-x)WO3–xPbO glass systems. The IR spectra of 60B2O3–10TeO2–(30-x)ZnO–xPbO glasses reveal that the glass network consists of [TeO3], [BO3], and [BO4] groups.