Temperature Dependence of Infrared Absorption Spectra of Hydroxyl Groups in Soda Germanate Glasses

Abstract

Infrared absorption spectra of hydroxyl stretching vibrations in soda germanate glasses were measured over the range from ambient temperature up to about their softening point. The spectrum of 5Na2O · 95GeO2 glass was found to consist of two absorption bands through an analysis of the spectral changes with temperature. One is located around 3550 cm−1, similar to the band seen in GeO2 glass. Another is centered around 3300 cm−1, also seen in 28Na2O · 72GeO2 glass. From the OH band position and the negative charge on the acceptor oxygen, the bonding configuration responsible for the latter band is considered to be an OH group forming a hydrogen bond with an oxygen bridging a 4Ge and a 6Ge (superscript: coordination number). The equilibrium between the two types of hydroxyl groups giving the above two bands was almost frozen at a temperature far below the Tg of the host glass.