Effect of heat treatment on the infrared absorption spectra of Sr-Na borosilicate glass

Internal modes of vibrations are studied here at different temperatures (27–800°C) and in the frequency range 200–4000 cm−1 through heat treatment. The baseline method was used. The strong bands of SiO4 tetrahedra in this glass show an increase in absorbance at high temperature (600–800°C). The deformation of SiO4 tetrahedra is investigated. This is found to depend on the ionic radius of the divalent metal oxide introduced, and the coordination number of the cation. Also from a study of the temperature dependence of the relative integrated intensity of the modes 600–800 and 850–1450 cm−1, the relaxation time and rotational energy barrier of the glasses selected indicate that the glassy phases are transformed to crystalline phases at ∼500°C.