ESR studies of hydrogen hyperfine spectra in irradiated vitreous silica

Various means of deuteration have been used to establish the hydrogenic origin of both the 119-G and 74-G hyperfine doublets observed in a variety of irradiated vitreous silica samples. The g values of both these defects appear inconsistent with an earlier model in which these lines were attributed to a hole localized on a hydroxyl group. Of the alternative models suggested by this experimental study, the most satisfactory attributes the 119-G doublet to an electron trapped at a hydrogen-compensated substitutional germanium impurity and the 74-G doublet to an electron trapped at a silicon atom adjacent to an oxygen vacancy and in the immediate neighborhood of a hydrogen, a defect termed the [E2′/H].