Author(s)

Gomaa El-Damrawi, Abdelmeguid K. Hassan, Salma Ehmead, Amal El Shahawy

Physics Department, Faculty of Science, Mansoura University, Mansoura, Egypt.

Microstructure of complicated glasses in the system 30Na₂O-2Al₂O₃-25 SiO₂-xCeO₂ (43-x) B₂O₃, x changes from 0.5 to 20 mol% have been extensively studied. Structural determination of glasses containing high cerium oxide content (≥8 mol% CeO₂) was carried out by ¹¹B NMR and FTIR spectroscopy. On the other hand, ²⁹Si MAS NMR experiment is hardly to be applied to glasses of CeO₂ > 8 mol%. This is due to the paramagnetic action which is raised by cerium cations causing dilution or delaying in the resonance phenomenon. It is evidenced from NMR data that sodium oxide is high enough to modify the glass forming units which constitute the skeleton of the glass. Ceria is as well as silica and B₂O₃ all are acting as glass forming species. Decreasing of both fraction of boron tetrahedral units (N4) and chemical shift of silicon nuclei (δ) confirm the role of CeO₂ as a glass former. On the other hand, fast decrease in N₄ and chemical shift of Si nuclei with further increasing CeO₂ contents (≥8 mol%) gives a clear evidence that the ability of cerium oxide to participate as a network former increases with increasing its content. New approach is applied to determine the fraction of CeO₄ as a glass forming units. In this approach, we use the common advantage of ¹¹B NMR and FTIR spectroscopy to obtain Ce4 fraction. The latter species cannot be determined from NMR spectroscopy, since very high relaxation time and magnetization of ceria cause intensive spectral broadening which prevent resonance spectra to be appeared.

NMR Spectroscpy, Cerium Oxide, New Approach, Glasses

El-Damrawi, G. , Hassan, A. , Ehmead, S. and Shahawy, A. (2017) Advantage of NMR and FTIR Spectroscopy to Determine Structure Role of CeO₂ in Complicated Borosilicate Glasses: New Approach. New Journal of Glass and Ceramics, 7, 22-33. doi: 10.4236/njgc.2017.72003.