Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1464999 | Ceramics International | 2006 | 7 Pages |
Abstract
The effects of Cr2O3 on the properties of (Zn, Co, Ta)-doped SnO2 varistors were investigated in this study. The samples with different Cr2O3 concentrations were sintered at 1400 °C for 2 h. The properties of (Zn, Co, Ta, Cr)-doped SnO2 varistors were evaluated by XRD, dilatometry, SEM, I–V and impedance spectroscopy. DC electrical characterization showed a dramatic increase in the breakdown electrical field and in the nonlinear coefficient with the increase in Cr2O3 concentration. The grain size was found to decrease from 13 to 5 μm with increasing the Cr2O3 content. The impedance data, represented by means of Nyquist diagrams, show two time constants, one at low frequencies and the other at high frequencies.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
F.M. Filho, A.Z. Simões, A. Ries, L. Perazolli, E. Longo, J.A. Varela,