A temperature dependence Raman study of the 0.1Nb₂O₅–0.9TeO₂ glass-forming system

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• 作者：Angelos G. Kalampounias ; George N. Papatheodorou and Spyros N. Yannopoulos
• 关键词：A ; Amorphous materials ; A ; Glasses ; A ; Non-crystalline materials ; A ; Oxides ; C ; Raman spectroscopy
• 刊名：Journal of Physics and Chemistry of Solids
• 出版年：2006
• 出版时间：April 2006
• 年：2006
• 卷：67
• 期：4
• 页码：725-731
• 全文大小：419 K

文摘

Raman spectra of the 0.1Nb₂O₅–0.9TeO₂ binary glass-forming oxide system were measured over a temperature range including the glassy, supercooled and crystalline state to reveal the structural changes caused by temperature variation. The analysis of the reduced Raman spectra made it possible to quantitatively follow the transformation of the TeO₄ trigonal bipyramids—that dominate in the low temperature glass—into TeO₃ trigonal pyramids with temperature rise. Based on the predictions of existing structural models, we estimated with the aid of the Raman data the number of terminal oxygen atoms that inevitably accompany this structural change. The various crystal phases of the system studied in this work and the routes for converting one crystal phase into another were also examined. Finally, the low-energy excitations of the non-crystalline states of 0.1Nb₂O₅–0.9TeO₂ were studied by following the temperature dependence of the Boson peak.