SiO2 gels produced by 4 and 16 mol water/mol Si(OC2H5)4 [TEOS] were densified at 1000°C and then exposed to γ-ray irradiation in order to produce paramagnetic defect centers. The paramagnetic defect centers detected in the sol-gel (n = 4,16) glasses depend on the mol H2O/mol TEOS ratio (n = 4,16) of the gels from which they wer derived. In the n = 16 sol-gel glass three different O2- ions were detected while in the n = 4 sol-gel glass the E′ center and the CO2- radical were observed. Some of these paramagnetic states were not found in the SiO2 glasses produced by the oxide melting techniques. These differences may suggest structural differences between the structures of the SiO2 glasses produced by the sol-gel and oxide melting techniques.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry