Reduction of Sm3+ and Eu3+ ions-co-doped Al2O3–SiO2 glasses and photoluminescence properties

Abstract

The reduction process of Sm3+ and Eu3+ ions doped in Al2O3–SiO2 glasses and the energy transfer phenomena between Sm2+ and Eu2+ ions were investigated. When the glass was heated with H2 gas, the H2 gas molecules diffused through the glass structure, followed by the reduction of Sm3+ to Sm2+ without forming AlOH bonds, whereas the Eu3+ ions reduced and formed AlOH bonds. The activation energy for the H2 gas diffusion in Sm3+-doped glass was higher than that of Eu3+-doped glass and the reduction of Sm3+ ions was suppressed as the Eu2O3 content increased. The photoluminescent properties caused by the energy transfer between Eu2+ and Sm2+ ions were also examined. The energy of the Eu2+:4f7→ 4f65 d1 transition effectively transferred to excite the Sm2+: 4f6→ 4f55 d1 transition, resulting in strongly enhanced emission intensities of the Sm2+: 5D0→7FJ transitions.