Effect of Fe2O3 concentration on the structure of the SiO2-Na2O-Al2O3-B2O3 glass system

The structural properties of the glass matrix 40SiO(2)center dot 30Na(2)O center dot 1Al(2)O(3)center dot(29-x)B2O3 center dot xFe(2)O(3) (mol%), 0.0 <= x <= 29.0 were studied by X-ray diffraction (XRD), differential thermal analysis (DTA) and Raman and infrared spectroscopy (FT-IR). XRD demonstrated Fe3O4 crystal formation for Fe2O3 concentrations of 29.0 mol%. DTA showed that glass transition and crystallization temperatures changed as a function of Fe2O3 concentration and that these alterations were related to structural change in the glass system. Interesting aspects of Raman and FT-IR spectra were found, and this gives information about of the structure changes in Si-O-Si units of these glasses as a function of Fe2O3 concentration. (C) 2011 Elsevier B.V. All rights reserved.