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首页> 外文期刊>Journal of Non-Crystalline Solids: A Journal Devoted to Oxide, Halide, Chalcogenide and Metallic Glasses, Amorphous Semiconductors, Non-Crystalline Films, Glass-Ceramics and Glassy Composites >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

机译：SiO2-Al2O3玻璃的结构：结合X射线衍射，IR和拉曼研究

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摘要

The average structures of roller-quenched (SiO2)(1-x)(Al2O3)(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% Al2O3 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% Al2O3 suggest the existence of AlO5 and AlO6 polyhedra. However, models of the first T-O peak in the radial distribution functions and the IR spectra indicate that the actual number of AlO5 polyhedra should be very small in these glasses. The polarized Raman spectra indicate that a homogeneous SiO2-Al2O3 network is formed in which the relative number of interconnected SiO4 tetrahedra gradually decreases with increasing Al2O3 content. Comparison with SiO2-Al2O3 liquid structures, previously derived from molecular dynamics simulations, suggest that the AlO5 species, which are dominant in the high-temperature liquids, transform to AlO4 and AlO6 species despite the relatively rapid quenching method used. (c) 2005 Elsevier B.V. All rights reserved.
机译：通过大角度X射线散射，IR和拉曼光谱分析了辊淬（SiO2）（1-x）（Al2O3）（x）的平均结构，x = 0.25、0.38、0.53和0.60。研究了Si和Al原子周围局部结构随组成的变化。含25和38 mol％Al2O3的玻璃的平均T-O距离与从离子半径计算出的平均四面体T-O距离非常相似。这些玻璃的估计配位数约为4。另一方面，具有53和60摩尔％的Al 2 O 3的玻璃的平均T-O距离和配位数表明存在AlO 5和AlO 6多面体。但是，径向分布函数中第一个T-O峰的模型和红外光谱表明，在这些玻璃中，AlO5多面体的实际数量应该很小。极化拉曼光谱表明形成了均匀的SiO2-Al2O3网络，其中互连的SiO4四面体的相对数量随着Al2O3含量的增加而逐渐降低。与先前从分子动力学模拟得出的SiO2-Al2O3液体结构的比较表明，尽管使用了相对快速的淬灭方法，但在高温液体中占主导地位的AlO5物种却转化为AlO4和AlO6物种。 （c）2005 Elsevier B.V.保留所有权利。

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