The structure of simple silicate glasses in the light of Middle Infrared spectroscopy studies

The aim of the work is to determine the internal structure of simple silicate glasses based on structural studies. Due to the absence of the long-range order, the X-ray methods usually applied in the studies of crystalline materials are of low applicability in the investigations of glasses. Therefore, spectroscopic methods, such as Middle Infrared (MIR), which make it possible to ‘see’ the short- and the middle-range orders are extremely suitable in their studies. MIR investigations have shown that the glasses studied exhibit domain composition, which corresponds to the order of certain crystalline phases. Analysis of the MIR spectra of simple silicate glasses and their mathematical decomposition allowed us to identify the bands characteristic for ring systems as well as those originating from Si–O−, Si = O defects. Appearance of the bands characteristic for pseudolattice ring vibrations (740–600 cm− 1) in the MIR spectra of glasses is an evidence of the existence of over-tetrahedral order.