FTIR spectra of pseudo-binary sodium borate glasses containing TeO2

The glass system xTeO2·(100 − x)[0.5Na2O·0.5B2O3] was prepared and measured for Fourier transform infrared spectroscopy. The results show that [BO3] and [BO4] were among the main structural units in the investigated glasses as well as [TeO3] and [TeO4] groups. Evidence was observed for the presence of boroxol rings in these glasses. By introducing TeO2 into the glass network, the concentration of Na2O which is connected with B2O3 network is changed and hence trigonal to tetrahedral boron ratio. When 50% of the total Na2O content was associated with TeO2 minimum number of [TeO3] units was observed in the glass network. With higher than 40 mol% TeO2, there is a constancy of the concentration of [TeO4] units. Bonds of the type B–O–Te are common at high concentrations of TeO2 (>40 mol%) which is associated with an increase in the polymerization of the glass network. Introducing TeO2 into Na2O·B2O3 glasses (1:1) may delay the expected disappearance of non-bridging oxygens (NBOs) in the whole glass network with the decrease in the content of sodium oxide.