Luminescence spectral properties of Sm-and (Ce, Sm)-containing silica gel glasses

Abstract

The spectroscopic behavior of Sm3+ ions is investigated in monoactivated and coactivated (with cerium) glasses obtained by the direct sol-gel-glass transition. It is shown that the majority of the Sm3+ ions form optical centers of the same type, whose luminescence spectral characteristics depend weakly on the concentration of the activator and the technique used to introduce it. Complex centers, including Sm3+ and Ce4+ ions bound by bridge oxygen, are also formed in the coactivated glass during the pore nucleation stage. The Sm3+ ions in these centers are characterized on the average by higher local symmetry, the efficient enhancement of luminescence by photoreduced (Ce4+)− ions, and its extinction by Ce-containing clusters.