Thermodynamic modeling and Raman spectroscopy study of Na2O-TiO2-SiO2 glasses

The glasses with composition xTiO(2)-(100-x)[40Na(2)O-60SiO(2)] (0 <= x <= 30 mol%) were studied using Raman spectroscopy and thermodynamic modeling. According to the thermodynamic modeling results, the chemical structure of studied glasses is defined by seven chemical groups (TiO2, SiO2, Na2O.2SiO(2), Na2O.SiO2, Na2O.3TiO(2), Na2O.TiO2, Na2O.TiO2.SiO2), whereas the short-range order (SRO) structures are TiO5, TiO6, Q4, Q(3) and Q(2) species. Existence of all these SRO structures was confirmed by the analysis of measured Raman spectra. The equilibrium molar amounts of SRO groups calculated in the framework of the Shakhmatkin-Vedishcheva thermodynamic model and those derived from spectroscopic data exhibit a positive correlation.