Optical properties and valence state of Sm ions in alumino-borosilicate glass under beta-irradiation

Sm-doped borosilicate glasses exposed to beta-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 P-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. (authors)