Author(s)

Gomaa El-Damrawi¹, Abdel Meguid Hassan¹, Rawia Ramadan², Sammer El-Jadal¹

¹Glass Research Group, Physics Department, Faculty of Science, Mansoura University, Mansoura, Egypt.
²Microwave and Dielectric Department, National Research Center, Dokki, Giza, Cairo, Egypt.

The structure of borosilicate glasses of composition 30Na₂O-2Al₂O₃-25SiO₂-xFe₂O₃ (43-x) B₂O₃ has been investigated in the composition range of 0.5 20 mol% Fe₂O₃. ²⁷Al, ¹¹B, ²⁹ Si MAS NMR and FTIR spectroscopies have been used to measure the fraction of different structural species in the glasses. It is evidenced from NMR data that both sodium and Fe₂O₃ (in low region up to 7 mol%) are the main glass modifier. Structural determination for borosilicate glasses with a high content of (Fe₂O₃) was carried out by FTIR spectroscopy, where both ¹¹B and ²⁹Si MAS NMR are impossible because of the high quantities of paramagnetic iron (III) species present. NMR analysis was performed on borosilicate glasses containing up to 7 mol% Fe₂O₃ and the N₄ values obtained by FTIR spectroscopy agree within error with the ¹¹B NMR results of the same glass samples. Fe₂O₃ is a main glass modifier in the low-Fe₂O₃-content region (≤6 mol%). On other hand, it plays the role of glass former at higher content of Fe₂O₃. Increasing both N₄ of boron tetrahedral units and chemical shift of silicon nuclei to reach maxima at 5 mol% Fe₂O₃ confirms the role of Fe₂O₃ as a glass modifier in the low composition region. On the other hand, fast decrease in N₄ with further increasing Fe₂O₃ contents ≥6 mol%) is an evidence for iron oxide to inter the glass network as a network former.

NMR-FTIR-Spectroscopy-Borosilicate-Glasses

El-Damrawi, G. , Hassan, A. , Ramadan, R. and El-Jadal, S. (2016) Nuclear Magnetic Resonance and FTIR Structural Studies on Borosilicate Glasses Containing Iron Oxide. New Journal of Glass and Ceramics, 6, 47-56. doi: 10.4236/njgc.2016.64006.