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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.)

Microscopic and thermodynamic interpretations of experimental data on ionic conductivity in lithium silicate glasses

Autor(es):
Ferreira Nascimento, Marcio Luis [1] ; Martins Rodrigues, Ana Candida [2] ; Souquet, Jean Louis [2, 3]
Número total de Autores: 3
Afiliação do(s) autor(es):
[1] Univ Fed Bahia, Inst Humanities Arts & Sci, Vitreous Mat Lab, BR-40170115 Salvador, BA - Brazil
[2] Univ Fed Sao Carlos, Dept Mat Engn, Lab Mat Vitreos, BR-13565905 Sao Carlos, SP - Brazil
[3] ENSEEG, Lab Electrochim & Physicochim Mat & Interfaces, F-38402 St Martin Dheres - France
Número total de Afiliações: 3
Tipo de documento: Artigo Científico
Fonte: PHYSICS AND CHEMISTRY OF GLASSES-EUROPEAN JOURNAL OF GLASS SCIENCE AND TECHNOLOGY PART B; v. 51, n. 1, p. 69-77, FEB 2010.
Citações Web of Science: 6
Resumo

Experimental data from the literature on electrical conductivity are reviewed for 43 glass compositions in the xLi(2)O-(1-x)SiO(2) system (0.05<x<0.67). The data are presented herein as a function of temperature and in isothermal plots as a function of the Li(2)O molar ratio, x. Below the glass transition temperature, T(g), the experimental ionic conductivity of all the compositions follows an Arrhenius law, sigma=sigma(0)exp(-E(A)/RT). The large quantity of experimental data minimizes the experimental inaccuracy in glass composition and conductivity measurements, thus allowing for accurate estimates of the mean values of the pre-exponential term (sigma(0)) of the Arrhenius expression and the activation energy (E(A)), as well as a precise assessment of the variations in isothermal conductivity with the molar ratio, x. The value of the pre-exponential term and the variation of isothermal conductivity and activation energy with x are then interpreted by reference to general concepts for ionic transport in solids, and to the so-called weak electrolyte theory. The Anderson \& Stuart model is employed to estimate the absolute values of activation energy. The association of the intrinsic cationic pair model and the weak electrolyte theory provides a good description of the variations in electrical conductivity and activation energy as a function of the Li(2)O molar ratio. The Anderson \& Stuart model leads to consistent absolute values of activation energy only if an arbitrarily chosen value of jump distance is employed in the corresponding expression. (AU)

Processo FAPESP: 04/10703-0 - Crescimento de cristais em vidros óxidos: testes de modelos e do possível desacoplamento entre difusão iônica e fluxo viscoso
Beneficiário:Marcio Luis Ferreira Nascimento
Linha de fomento: Bolsas no Brasil - Pós-Doutorado
Processo FAPESP: 07/08179-9 - Processos cinéticos em vidros e vitrocerâmicas
Beneficiário:Edgar Dutra Zanotto
Linha de fomento: Auxílio à Pesquisa - Temático
Processo FAPESP: 07/03563-5 - Jean Louis souquet | Institut National polytechnique Grenoble - França
Beneficiário:Ana Candida Martins Rodrigues
Linha de fomento: Auxílio à Pesquisa - Pesquisador Visitante - Internacional