Artigo
Analysis of secondary phases segregated and precipitated in SnO2-based varistors
Fecha
2005-04-01Registro en:
Journal of the European Ceramic Society. Oxford: Elsevier B.V., v. 25, n. 4, p. 401-406, 2005.
0955-2219
10.1016/j.jeurceramsoc.2004.02.010
WOS:000226924100011
Autor
UNMdP
Universidade Estadual Paulista (Unesp)
Resumen
Transmission and scanning electron microscopy techniques were used to study the heterogeneities found in the microstructure of (SnO2Co3O4Nb2O5Fe2O3)-Co-.-Nb-.-Fe-. and (SnO2ZnONb2O5FC2O3)-Zn-.-Nb-.-F-. varistors. Second phases encountered both inside the grains and ingrain boundary regions were identified using energy dispersive spectrometry and electron diffraction patterns. Through the electrical characterisation, the presence of iron oxide among the additives was determined to highlight the non-linear properties of the specimens. A discussion on the influence of second phases on the non-linear features of these systems is also addressed. (C) 2004 Elsevier Ltd. All rights reserved.