Design of low scattering and IR transparent glasses on the base of constant stoichiometry groupings concept

Abstract

Structural studies of PbO–GeO2 glasses have been carried out by Raman and infrared (IR) spectroscopy to study the interaction of initial oxides forming constant stoichiometry groupings (CSG). The Raman spectra of glasses are interpreted as superposition of relatively small number of unchangeable spectral forms belonging to CSG. This approach can be used to explain, calculate and predict some properties depending on the glass content. The concept of CSG opens the way to elaboration of low scattering and IR transparent glasses. The developed approach makes it possible to design low scattering glasses built from CSG of a single type. Correlations between Raman scattering and Rayleigh scattering measurement results for PbO–GeO2, PbO–SiO2 and Na2O–Al2O3–P2O5 glasses were found. Based on the measured Raman spectra we have proposed an explanation, which is able to predict the Boson peak frequency and its intensity correlations with the glass transition temperature. This prediction gives excellent agreement with the experimentally obtained data in PbO–GeO2, Na2O–B2O3 and BaO–B2O3 glasses.