Structural, mechanical and optical investigations in the TeO2-rich part of the TeO2–GeO2–ZnO ternary glass system
| Autor: | F. Gouraud, R. Karray, Philippe Thomas, Maggy Dutreilh-Colas, T. Chotard, Jean-René Duclere, N. Ghribi, A. Kabadou |
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| Přispěvatelé: | Laboratoire des Sciences des Matériaux et d'Environnement, Sfax, Université de Sfax - University of Sfax, Axe 3 : organisation structurale multiéchelle des matériaux (SPCTS-AXE3), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Axe 1 : procédés céramiques |
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Tellurite glasses
Materials science Optical properties Band gap Analytical chemistry Oxide Mineralogy Mechanical properties General Chemistry [CHIM.MATE]Chemical Sciences/Material chemistry Condensed Matter Physics [SPI.MAT]Engineering Sciences [physics]/Materials chemistry.chemical_compound symbols.namesake Differential scanning calorimetry chemistry Raman spectroscopy symbols General Materials Science Thermal stability Ternary operation Glass transition Refractive index |
| Zdroj: | Solid State Sciences Solid State Sciences, Elsevier, 2015, 40, pp.20-30. ⟨10.1016/j.solidstatesciences.2014.12.009⟩ |
| ISSN: | 1293-2558 |
| DOI: | 10.1016/j.solidstatesciences.2014.12.009⟩ |
| Popis: | Stable glasses are successfully synthesized in the TeO 2 -GeO 2 -ZnO system at 850 °C by the melt-quenching method and the glass forming domain is determined in the TeO 2 -rich part of the diagram. The thermal study, carried out using differential scanning calorimetry, reveals that the glass transition temperature, as well as the thermal stability, increases with the addition of ZnO or GeO 2 . Bulk glass samples are elaborated within two series of compositions, corresponding to fixed concentrations in GeO 2 (respectively 5 or 10 mol. %), and to various contents in ZnO. Structural changes caused by the ZnO addition are discussed based on Raman spectroscopy data. A progressive but very moderate network depolymerization is shown with increasing amount of ZnO. However, two different regimes can be identified, depending on the ZnO content. It is believed that ZnO acts as a network modifier for compositions below 20 mol. %, and starts to participate as a glass network former over such concentration. It is well evidenced that GeO 2 contributes to the increase in Young's modulus E , evaluated from ultrasonic echography measurements. In addition, this oxide favors the network reticulation detected by the decrease of the Poisson ratio and the increase of the fractal bond connectivity. However, the role of ZnO is more complicated and will be extensively discussed. The decrease in the atomic packing density C g probably explains the global evolution of E as a function of ZnO content. The refractive indices and optical band gap energies are extracted from UV-Visible-NIR optical transmission data. For the studied glasses, it is found that the transmission threshold decreases with larger ZnO contents, reflecting the increase in the optical band gap value. Refractive index is finally seen to decrease as a function of both ZnO and GeO 2 contents. Such variation is explained by the decrease of the molar electronic polarizability, and by the lower optical basicity values known for TeO 3 entities in comparison to TeO 4 units. |
| Databáze: | OpenAIRE |
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