Terminal Oxygens in Amorphous TeO2
Terminal Oxygens in Amorphous TeO2
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DOI：
10.1021/jz4010637
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发表时间：
2013-07-18
影响因子：
5.7
通讯作者：
Feller, Steve
中科院分区：
文献类型：
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作者：
Barney, Emma R.;Hannon, Alex C.;Feller, Steve
了解单组分玻璃的结构对于开发更复杂的多组分玻璃的结构模型至关重要。目前，亚碲酸盐系统的此类模型纯粹是定性的。这项研究展示了纯非晶 TeO2 结构的中子衍射和拉曼光谱测量，表明它是由三分之二的 [TeO4] 伪三方双锥体和三分之一的 [TeO3] 三方锥体与末端氧的组合而成。这与 TeO2 的所有晶体多晶型物形成鲜明对比，TeO2 的所有晶体多晶型物仅由四配位单元形成。利用这一结果，开发了一个定量模型，成功预测了一系列亚碲酸钾玻璃 xK(2)O 中心点(100 - x)TeO2 的平均 Te-O 配位数 (TeO)-Te-n。由于亚碲酸盐网络中存在末端氧原子，观察到的 nTeO 在 15 mol% K2O 时保持恒定。
Understanding the structure of single-component glasses is essential for developing structural models of more complex multicomponent glasses. Currently, such models for tellurite systems are purely qualitative. This study presents neutron diffraction and Raman spectroscopy measurements of the structure of pure amorphous TeO2, showing that it is formed from a combination of two-thirds [TeO4] pseudo-trigonal bipyramids and one-third [TeO3] trigonal pyramids with a terminal oxygen. This is in contrast to all crystalline polymorphs of TeO2, which are formed solely from the four-coordinated units. Using this result, a quantitative model has been developed that successfully predicts the average Te-O coordination number, (TeO)-Te-n, for a series of potassium tellurite glasses, xK(2)O center dot(100 - x)TeO2. The observed nTeO is constant up to 15 mol % K2O due to the presence of terminal oxygen atoms in the tellurite network.