Ca and Na environments in Na2O-CaO-Al2O3-SiO2 glasses:: influence of cation mixing and cation-network interactions
Ca and Na environments in Na2O-CaO-Al2O3-SiO2 glasses:: influence of cation mixing and cation-network interactions
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DOI：
10.1016/j.chemgeo.2004.08.049
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发表时间：
2004-12-15
期刊：
影响因子：
3.9
通讯作者：
Neuville, DR
中科院分区：
文献类型：
--
作者：
Cormier, L;Neuville, DR
利用Ca和Na k边x射线吸收光谱和分子动力学（MD）模拟研究了钠石灰铝硅酸盐玻璃中的Ca和Na环境。x射线吸收近边结构（XANES）光谱和MD计算表明，在扭曲多面体中，Ca的配位数约为7，Na的配位数约为6。Ca和Na XANES光谱受到Si/Al取代或Ca/Na取代的影响很小，而MD模拟在阳离子环境中呈现出一些变化。我们发现非桥接氧（NBOs）更倾向于与Ca连接而不是与Na连接。MD模型显示了Ca- na混合的证据，并且富钙铝硅酸盐玻璃有形成更多富（Ca, NBOs）区域的趋势。Na/Ca取代后阳离子迁移率的变化与观察到的结构修饰有关。(C) 2004 Elsevier B.V.版权所有
X-ray absorption spectroscopy at Ca and Na K-edges and Molecular Dynamics (MD) simulations are used to investigate the Ca and Na environment in soda lime alummosilicate glasses. Both X-ray Absorption Near Edge Structure (XANES) spectra and MD calculations indicate a coordination number of about 7 for Ca and 6 for Na, in a distorted polyhedron. Ca and Na XANES spectra are poorly affected either by the Si/Al substitution or the Ca/Na substitution while MD simulations present some variations in the cationic environment. We show an affinity for non-bridging oxygens (NBOs) to be connected with Ca rather than Na. Evidence of Ca-Na mixing is shown by the MD models and there is a tendency toward forming more regions enriched in (Ca, NBOs) for CaO-rich alummosilicate glasses. Variations in the cationic mobility upon the Na/Ca substitution are correlated with the observed structural modifications. (C) 2004 Elsevier B.V. All rights reserved.