Boiko, A. A.

Boiko, V. A.

Poddenezhny, E. N.

Strek, W.

Electronic Library Pavel Sukhoi State Technical University of Gomel (GSTU)

Р64SILICA GLASS AND NANOCOMPOSITES DOPED WITH Fe3+- AND Co2+-IONS PREPARED BY SOL-GEL PROCESSA.A. Boiko, E.N. Poddenezhny*, V.A. Boiko, W. Str^k**Gomel State Technical University, 48 October Av., 216716 Gomel, BelarusGomel State University, 104 Sovietskaya St., 246699 Gomel, BelarusInstitute for Low Temperature and Structure Research, Polish Academy of Sciences, 2 Okolna St., 50-950 Wroclaw, PolandIron and cobalt-containing silica glasses and nanostructures can be used as ferromagnetic materials and color filters [1,2]. Utilization of the sol-gel process for synthesis of silica glass is preferable because its low sintering temperature and high efficiency. Incorporation of fluorine into xerogel simultaneously with Fe- and Co-ions reduces bubble formation upon consideration by sintering and results in the formation of Fe- and Co-containing clusters in the network of silica gel-glass.The Fe- and Co-doped glasses and composites were prepared by hybrid sol-gel process [3], modified in the part of doping technique. The flowchart of hybrid sol-gel process shows in figure.The resulting gels were dried at 30-60°C in the period 7-14 days in air and presintered at 600°C in 2 hours. After thermo-treatment the xerogels were impregnated by water or organic solutions of CoCl2-6H2O or FeCl3-6H2O.The pore-size distribution in the gel structure measred by BET-Method has a complex character; the network contents micropores (3.0 run), mezo- and macro-pores (5.0-25.0 nm). The pore size can be enlarged by chemical attack of silica network by fluorine ions in solution and also in vapor phase until heating and dissociation of Fe- and Co-containing compounds (HF, NH4F).The following thermo-treatment of Fe- and Co-containing xerogels in air at temperatures 600-1200°C lead to formation of silica glasses, containing 2000-2500 ppm of OH groups. The UV-Vis spectra and XDR-investigation shows both the presence of oxide- and fluoride-containing silica composites was equal to 100-200 p.m.The models of (Me^k nanosized clusters in the structure of silica gel-matrices were proposed after studying of morphology and optical parameters.REFERENCES1. T. Akiyama, E. Tanigawa, T. Ida, Chemistry Letters, 1998, 723.2. P.S. Schultz, J. Am. Ceram. Soc., 57, 309, 1974.3. G.E. Malashkevich, E.N. Poddenezhny, I.M. Melnichenko et al., J. Non-Cryst. Sol., 188, 107, 1995.

Silica glass and nanocomposites doped with Fe3+- and Co2+-ions prepared by sol-gel process

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Silica glass and nanocomposites doped with Fe3+- and Co2+-ions prepared by sol-gel process

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