Structure and properties of Na2O-TiO2-SiO2 glasses: Role of Na and Ti on modifying the silica network

• Structure and properties of xNa2O-yTiO2-(1-x-y)SiO2 glasses were systematically studied.
• The modifying role of Na and Ti on silica network was illustrated through Raman spectra.
• Structure and thermo-mechanical properties correlation was established.

Changes in the structure and properties of xNa2O-yTiO2-(1-x-y)SiO2 glasses have been studied with regards to composition through Raman spectroscopy, Brillouin light scattering, and dilatometry. Twelve glasses with compositions x = 10, 15, 20, and 25, and y = 4, 7, and 10 were prepared through a traditional melt quench method. Na2O was found to increase the density, refractive index, coefficient of thermal expansion (CTE), bulk modulus, and Poisson's ratio of glasses, and to decrease Young's modulus and shear modulus. Density, refractive index, Young's modulus, shear modulus, bulk modulus and Poisson's ratio increase with the increase of TiO2 content. CTE was found to increase with the initial addition of 4 mol% TiO2 and to remain constant with further additions, regardless of the Na2O content. Changes in the Raman spectra with composition have been discussed and related to the changes in resulting properties.