Effect of oxidizing and reducing atmospheres on the electrical properties of dense SnO2-based varistors


Autoria(s): Santos, MRC; Bueno, Paulo Roberto; Longo, Elson; Varela, José Arana
Contribuinte(s)

Universidade Estadual Paulista (UNESP)

Data(s)

20/05/2014

20/05/2014

01/02/2001

Resumo

The SnO2 based varistor systems recently presented in the literature appear to have a promising potential in commercial applications. Experimental evidence shows that there is a dependence of nonlinear constant values with thermal treatment under different atmospheres. Thermal treatments in oxygen and nitrogen rich atmospheres at 900 degreesC prove this dependence, indicating that the nonlinear constant values are significantly lower when the material is submitted to a nitrogen atmosphere. Moreover, electrical properties can be restored when the varistor is subjected to thermal treatment at the same temperature in an oxygen atmosphere, indicating that the mechanism seems to be reversible. This paper discusses this behavior focusing in the grain boundary region. Ta2O5 mol% concentrations are also analyzed and the results indicate an optimum Ta2O5 concentration of 0.05 mol% for the electrical properties (alpha = 44 and E-B = 6150 V cm(-1)). (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Formato

161-167

Identificador

http://dx.doi.org/10.1016/S0955-2219(00)00177-1

Journal of the European Ceramic Society. Oxford: Elsevier B.V., v. 21, n. 2, p. 161-167, 2001.

0955-2219

http://hdl.handle.net/11449/32510

10.1016/S0955-2219(00)00177-1

WOS:000166551300008

Idioma(s)

eng

Publicador

Elsevier B.V.

Relação

Journal of the European Ceramic Society

Direitos

closedAccess

Palavras-Chave #electrical properties #grain boundaries #SnO2 #Ta2O5 #varistors
Tipo

info:eu-repo/semantics/article