Effect of sintering temperature on microstructure and nonlinear electrical characteristics of ZnO varistor

The nonlinear properties of ZBMCCS-based varistors, which are composed of ZnO–Bi2O3–MnO2–Cr2O3–Sb2O3–Co3O4 and SiO2 are studied inrelation to sintering temperature, in the range of 1280–1350∘C. The samples are investigated for grain morphology by using scanning electron microscope (SEM). These sampl...

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Bibliographic Details
Main Authors: Ahmed Bouchekhlal, Farida Hobar
Format: Article
Language:English
Published: World Scientific Publishing 2018-04-01
Series:Journal of Advanced Dielectrics
Subjects:
Online Access:http://www.worldscientific.com/doi/pdf/10.1142/S2010135X18500145
Description
Summary:The nonlinear properties of ZBMCCS-based varistors, which are composed of ZnO–Bi2O3–MnO2–Cr2O3–Sb2O3–Co3O4 and SiO2 are studied inrelation to sintering temperature, in the range of 1280–1350∘C. The samples are investigated for grain morphology by using scanning electron microscope (SEM). These samples were examined by using X-ray diffraction patterns (XRD) and DC electrical measurements. X-ray diffraction analysis of the samples show the presence of ZnO, Zn2SiO4 willemite phase and Co2.33Sb0.67O4 spinel phases.The average grain size of ZnO increased as the sintering temperature increased from 2.57 to 6.84 μm. In the examined temperature range, the breakdown field decreased from 2992 to 127V/cm with the increase of sintering temperature. This system gives a relatively high nonlinearity coefficient α=33.61 (at a sintering temperature of 1280∘C) with a low leakage current of 0.21mA/cm2.
ISSN:2010-135X
2010-1368