Annealing effects in SiO2–Na2O glasses investigated by Brillouin scattering

Abstract The elastic energy due to residual stresses in non-annealed SiO 2 –Na 2 O glasses is determined in the frame of the theory of elasticity, assuming that a non-annealed glass can be considered as a distorted material in comparison with the annealed glass. An analysis of the elastic energy which is released at annealing is presented. Using hypotheses concerning the localisation of this energy in the glass and structural relaxation at annealing has allowed us to recalculate values of cation vibrational mode frequencies measured by infrared spectroscopy. The annealing effects on mechanical properties are studied and analysed in terms of glass structure, including phase separation at low sodium concentration.