Figure 4. Thermal and mechanical reponse of densified silica glass.

Longitudinal Brillouin frequency shift as a function of temperature (A) and pressure (B) for cold-compressed and hot-compressed silica glass. Note: Data for cold-compressed silica glass in (A) was taken from Grimsditch³², where the closed squares were measured at the specified temperature (in-situ) and the open squares were measured at room temperature after annealing at the specified temperature (ex-situ), each after an hour annealing. Data in this study were all measured in-situ, after 10 minutes at the specified temperature. Data for cold-compression of silica glass in (B) was taken from Sonneville et al.⁹. Inset: longitudinal Brillouin frequency shift of hot-compressed silica glass as a function of testing pressure during compression up to 15–16 GPa at room temperature.