Eγ′ 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 Eγ′ 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 Eγ′ 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 Eγ′ center generation.