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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.)

Electronic conductivity of vanadium-tellurite glass-ceramics

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Autor(es):
Kjeldsen, Jonas [1] ; Yue, Yuanzheng [1] ; Bragatto, Caio B. [2] ; Rodrigues, Ana C. M. [2]
Número total de Autores: 4
Afiliação do(s) autor(es):
[1] Aalborg Univ, Sect Chem, DK-9000 Aalborg - Denmark
[2] Univ Fed Sao Carlos, Dept Mat Engn, BR-13565905 Sao Carlos, SP - Brazil
Número total de Afiliações: 2
Tipo de documento: Artigo Científico
Fonte: Journal of Non-Crystalline Solids; v. 378, p. 196-200, OCT 15 2013.
Citações Web of Science: 12
Resumo

In this paper, we investigate the electronic conductivity of 2TeO(2)-V2O5 glass-ceramics with crystallinity ranging from 0 to 100 wt.%, i.e., from entirely amorphous to completely crystalline. The glass is prepared by the melt quenching technique, and the crystal is prepared by subsequent heat treatment thereof. Glass-ceramics are prepared by mixing glass and crystal powder, followed by a sintering procedure. Activation energies for electronic conduction in the glass and in the crystal are determined by fitting the Mott-Austin equation to the electronic conductivity data obtained by impedance spectroscopy. We find similar activation energies for both glass and crystal, implying that they have similar conduction mechanisms, i.e., thermally activated hopping. The electronic conductivity of 2TeO(2)-V2O5 glass is about one order of magnitude higher than that of the corresponding crystal, and a percolation phenomenon occurs at a glass fraction of 61 wt.%, increasing from a lower conductivity in the crystal to a higher conductivity in the glass. We explain the behavior of electronic conduction in the 2TeO(2)-V2O5 glass-ceramics by considering constriction effects between particles as well as percolation theory. This work implies that, based on its electronic conductivity, vitreous 2TeO(2)-V2O5 is more suitable as a cathode material in secondary batteries compared to a 2TeO(2)-V2O5 glass-ceramic. (C) 2013 Elsevier B.V. All rights reserved. (AU)

Processo FAPESP: 07/08179-9 - Processos cinéticos em vidros e vitrocerâmicas
Beneficiário:Edgar Dutra Zanotto
Linha de fomento: Auxílio à Pesquisa - Temático