Structure and thermo-mechanical response of TiO2-SiO2 glasses to temperature

• Thermo-mechanical response of TiO2-SiO2 glasses to temperature were studied.
• TiO2-SiO2 glasses prepared by sol-gel and flame hydrolysis deposition were compared.
• A possible explanation for the anomalies in TiO2-SiO2 glasses was suggested.

Structure and elastic moduli of xTiO2 - (1 − x) SiO2 (x = 0–10 mol%) glasses prepared via the sol-gel process have been investigated through in-situ high temperature Raman and Brillouin light scattering from room temperature to 1200 °C. Three other synthetic glasses prepared by the flame hydrolysis deposition (FHD) process, namely, synthetic silica glass (Corning 7980) and two titania silicate glasses (x = 5.4 and 8.3), were also examined under the same conditions. The coefficients of thermal expansion of sol-gel glasses were measured up to 800 °C. Differences in properties of sol-gel glasses, FHD glasses, and literature values are presented and discussed. Changes in elastic moduli and Raman peak positions with composition and temperature are discussed. Young's modulus, bulk modulus, and shear modulus were found to decrease with increasing TiO2 content and increase with temperature. A possible explanation for the anomalies in TiO2-SiO2 glasses is suggested based on the response of elastic moduli, Raman spectra, and coefficients of thermal expansion to temperature.