Structural evolution and its influence on luminescence of SiO2-SrF2-ErF3 glass ceramics prepared by sol-gel method

Er3+ doped SrF2-SiO2 transparent glass ceramics were prepared by sol-gel method and heat treatment. The decomposition of Sr2+-CF3COO- and the formation of SrF2 nano-crystals were found to proceed synchronously in the xerogel. After crystallization of the xerogel, SrF2 nano-crystals with 8-10 nm in size distributed homogenously among the glassy matrix, and the microstructure of the glass ceramic was stable under and at the temperature of 800 degrees C probably due to interfacial interaction between nano-crystals and glassy matrix. When heat-treated at 800 degrees C, the chemically bonded water in the sample was eliminated, resulting in the appearance of the visible luminescence bands of H-2(11/2) (4)S(3/)2 -> I-4(15/2) and F-4(9/2) -> I-4(15/2) transitions. (c) 2005 Elsevier B.V. All rights reserved.