Optical properties and valence state of Sm ions in aluminoborosilicate glass under β-irradiation

Sm-doped borosilicate glasses exposed to β-irradiation with doses from 8 × 105 up to 4 × 109 Gy have been studied by luminescence, Raman and electron paramagnetic resonance (EPR) spectroscopies. The luminescence spectra for pristine and irradiated glasses reveal that the β-irradiation process affects valence state of samarium ions. Intense emission at 684 and 727 nm excited by Ar+ laser (514.5 nm) due to the transition of Sm2+ ion was observed after irradiation. Relative proportion of Sm2+ ions estimated as a function of both Sm2O3 content and irradiation dose has the tendency to increase with increasing irradiation dose. In contrast, the EPR spectra of the studied samples reveal a decrease of the defect content, which are mostly hole defects, produced during irradiation, as a function of Sm2O3 content. Finally, the addition of Sm2O3 leads to a decrease of the Si–O–Si bending vibration modes shift and polymerisation changes under irradiation.