Structure of SiO2–Al2O3 glasses: Combined X-ray diffraction, IR and Raman studies

Masayuki Okuno, Nikolay Zotov, Martin Schmücker, Hartmut Schneider

doi:10.1016/j.jnoncrysol.2005.01.014

Abstract The average structures of roller-quenched (SiO 2 ) 1− x (Al 2 O 3 ) x , x = 0.25, 0.38, 0.53 and 0.60, glasses have been analyzed by large-angle X-ray scattering, IR and Raman spectroscopies. The changes of the local structure around the Si and Al atoms with composition are investigated. The average T–O distances for the glasses with 25 and 38 mol% Al 2 O 3 are very similar to the average tetrahedral T–O distances calculated from ionic radii. The estimated coordination numbers of these glasses are about 4. On the other hand, the average T–O distances and coordination numbers of the glasses with 53 and 60 mol% Al 2 O 3 suggest the existence of AlO 5 and AlO 6 polyhedra. However, models of the first T–O peak in the radial distribution functions and the IR spectra indicate that the actual number of AlO 5 polyhedra should be very small in these glasses. The polarized Raman spectra indicate that a homogeneous SiO 2 –Al 2 O 3 network is formed in which the relative number of interconnected SiO 4 tetrahedra gradually decreases with increasing Al 2 O 3 content. Comparison with SiO 2 –Al 2 O 3 liquid structures, previously derived from molecular dynamics simulations, suggest that the AlO 5 species, which are dominant in the high-temperature liquids, transform to AlO 4 and AlO 6 species despite the relatively rapid quenching method used.

Structure of SiO2–Al2O3 glasses: Combined X-ray diffraction, IR and Raman studies

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Structure of SiO2–Al2O3 glasses: Combined X-ray diffraction, IR and Raman studies

書誌事項

この論文をさがす

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収録刊行物

被引用文献 (20)*注記

詳細情報 詳細情報について

書き出し

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