Luminescence and microstructure of Sm2+ ions reduced by x-ray irradiation in Li2O–SrO–B2O3 glass

Abstract

Sm 3 + -doped Li2O–SrO–B2O3 glass sample was prepared by the conventional melt quenching method in air atmosphere. Sm2+ ions in this borate glass were obtained by x-ray irradiation reduction method. The as-prepared and x-ray-irradiated samples were investigated by photoluminescence spectrum and decay curve measurements. The dependence of Sm2+ luminescence intensity on the x-ray irradiation time was investigated. It is found that the conversion of Sm3+→Sm2+ after x-ray irradiation is efficient in this borate glass. Photostability of Sm2+ ions was evaluated by the photobleaching method. Furthermore, the induced optical absorption spectrum measurement after x-ray irradiation was performed. Thermoluminescence above room temperature was also studied after x-ray irradiation. The different kinds of defect structures and the reduction mechanism of Sm2+ ions in this borate glass were discussed. The microstructure of Sm ions in the Li2O–SrO–B2O3 glass was suggested. The proposed microstructure would be helpful to understand the reduction mechanism of Sm2+ ion in borate glasses.