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Browsing by Subject "krzemiany"

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  • thumbnail.journal.alt
    Item type:Book, Access status: Restricted ,
    Krystalochemia krzemianów
    (AGH. Uczelniane Wydawnictwa Naukowo-Dydaktyczne, 2008) Handke, Mirosław
  • thumbnail.journal.alt
    Item type:Doctoral Dissertation, Access status: Open Access ,
    Spektroskopia oscylacyjna pierścieni krzemotlenowych w strukturach krzemianów i siloksanów
    (2003-09-29) (Data obrony: 2007-06-15) Jastrzębski, Witold
    Wydział Inżynierii Materiałowej i Ceramiki
    Silicates and siloxanes are an important group of chemical compounds. Most silicates (cyclosilicates, phyllosilocates, tectosilicates) are composed of silicooxygen rings. The aim of this work is to better understand vibrational spectra of cyclosilicates by modeling spectra of properly chosen siloxanes (which are easier to understand being the spectra of molecular crystals). Ab initio calculations for different silicooxygen clusters are the tool which permits to interpret spectra of siloxanes. As a result of such procedure, the "ring bands" in pseudolattice (600-800 cm-1) region are distinguished. Ring bands are divided into the characteristic ones (symmetric and antisymmetric involving the whole ring) and other ring bands. Furthermore, characteristic bands for $Si_{4}O_{4}, Si_{6}O_{6}, Si_{8}O_{12}$ and $Si_{12}O_{18}$structural units are described.