Eu3+-activated silica prepared by the alkoxide sol-gel method

For the preparation of europium(III) activated silica tetraethoxysilane and europium(III) chloride were used as precursors. Powders and monoliths were prepared. The products were characterized by thermal analysis, scanning el ectron microscopy, ultraviolet-visible absorption spectroscopy, fluorescenc e spectroscopy, cathodoluminescent measurements, and extended x-ray absorpt ion fine structure (EXAFS) analysis. With EXAFS analysis we elucidated the environment of Eu3+ ions in amorphous samples. The Eu-O distance was 0.248 nm in xerogel and 0.23-0.26 nm in the powder after heating. (C) 2000 Americ an Vacuum Society. [S0734-211X(00)04002-6].