Eu[sup 3+]-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 electron microscopy, ultraviolet-visible absorption spectroscopy, fluorescence spectroscopy, cathodoluminescent measurements, and extended x-ray absorption 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.