centers induced by γ irradiation in sol–gel synthesized oxygen deficient amorphous silicon dioxide

The effects of room temperature γ-ray irradiation up to a dose of ∼1300 kGy are investigated by Electron paramagnetic resonance (EPR) measurements in amorphous silicon dioxide (a-SiO2) produced by a sol–gel synthesis method that introduces OSiSiO oxygen deficiency. We have found that exposure to radiation generates the E γ ′ center with the same spectral features found in high purity commercial a-SiO2. The maximum concentration of defects induced in this sol–gel material indicates that its resistance to radiation is comparable to that of synthetic fused a-SiO2. The concentration of E γ ′ center increases with irradiation, featuring a sublinear dose dependence up to the highest investigated dose and showing no saturation effects. This defect generation process suggests that the chemically induced precursor influences the mechanisms of E γ ′ center generation.