Optical properties of pristine and γ-irradiated Sm doped borosilicate glasses

The luminescence of pristine and γ-irradiated Sm3+ doped borosilicate glasses was studied as a function of Sm content. For these glass compositions, observed critical concentration for the appearance of luminescence quenching is less than 1 wt% of Sm2O3. The fluorescence spectra reveal that the reduction processes of Sm3+ to Sm2+ ions is accomplished in case of exposure glass composition to ionizing radiation like γ rays, while the Sm2+ ions are not present into the pristine samples. The luminescence intensity of Sm2+ ions is discussed in relation to the irradiation dose and magnification under micro Raman spectrometer. It is assumed that the divalent rare-earth ions are preferentially located in the bulk than near the surface of glass. Results on reduction of Sm3+ are also discussed in correlation with defects creation processes analysed by EPR spectroscopy.