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

Abstract

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.