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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Mixed network former effects in tellurite glass systems: Structure/property correlations in the system (Na2O)(1/3)[(2TeO(2))(x)(B2O3)(1) (- x)](2/3)

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Larink, Dirk [1] ; Eckert, Hellmut [1, 2]
Total Authors: 2
[1] WWU Munster, Inst Phys Chem, D-48149 Munster - Germany
[2] Univ Fed Sao Carlos, Inst Fis Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Journal of Non-Crystalline Solids; v. 426, p. 150-158, OCT 15 2015.
Web of Science Citations: 5

Mixed-network former effects upon glass transition temperatures, densities and electrical conductivities have been studied in glasses in the system (Na2O)(1/3){[}(2TeO(2))(x)(B2O3)(1) (-) (x)](2/3). Mixing of network formers B2O3 and TeO2 has a negative effect on ionic conductivities. Possible structural origins of this behavior have been studied by B-11, Na-23, and Te-125 high-resolution and dipolar solid state nuclear magnetic resonance (NMR) techniques, O-1s X-ray photoelectron spectroscopy and Raman spectroscopy. A quantitative structural model has been developed that is consistent with all of the experimental data, and provides a detailed description of network modification processes, interactions and connectivities. All the O-1s XP spectra can be satisfactorily fitted with two line shape components with the parameters of the binary end-member glasses, providing no evidence for the possible formation of B-O-Te linkages. In addition, none of the Te-125 and B-11 NMR data shows significant proof of such linkages, even though their formation cannot be explicitly excluded. Na-23 NMR data indicate a monotonic chemical shift trend consistent with proportional sharing of the network modifier between the two network former species. The experimental data suggest a tendency towards an avoidance of B-O-Te linkages, even though no macroscopic phase separation is observed. Nevertheless, the negative mixed network former effect can be rationalized in terms of compositionally segregated sodium borate and sodium tellurite nano-domains. (C) 2015 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass
Grantee:Edgar Dutra Zanotto
Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC