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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

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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Autor(es):
Larink, Dirk [1] ; Eckert, Hellmut [1, 2]
Número total de Autores: 2
Afiliação do(s) autor(es):
[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
Número total de Afiliações: 2
Tipo de documento: Artigo Científico
Fonte: Journal of Non-Crystalline Solids; v. 426, p. 150-158, OCT 15 2015.
Citações Web of Science: 5
Resumo

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)

Processo FAPESP: 13/07793-6 - CEPIV - Centro de Ensino, Pesquisa e Inovação em Vidros
Beneficiário:Edgar Dutra Zanotto
Linha de fomento: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs