6533b871fe1ef96bd12d118c

RESEARCH PRODUCT

Ge-doping dependence of gamma-ray induced germanium lone pair centers in Ge-doped silica

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We report an experimental study on the y irradiation effects in Ge-doped sol-gel silica samples doped with Ge from 10 2 up to 10 4 part per million molar. The samples were exposed to the radiation generated by a 60 Co source up to an accumulated dose value of 10 MGy. Our data evidence that the γ irradiation significantly increases the number of Germanium Lone Pair Centers (GLPC). Such defects are induced with a concentration that depends on the Ge content of the employed material in those samples where no optical activity related to -s GLPC was detected before irradiation. Furthermore an increase of the GLPC concentration was detected also in a sample that already contains this defect after the production., These findings show that, in addition to the GLPC bleaching.;', effect already reported in the literature, γ rays can generate such defects and a range of doses exists in which the generation processes overcome the bleaching processes.