Influence of Cr₂O₃ on the Residual Voltage Ratio of SnO₂‐Based Varistor

Abstract

The SnO2‐based varistor is a kind of new varistor ceramic material with high nonlinear electrical properties and high thermal conductivity. To improve the comprehensive performance, we focus on how to lower the residual voltage ratio of SnO2‐based varistor. In this article, the influence of Cr2O3 on the microstructure, nonlinear J–E characteristics and surge current performances have been investigated. By changing mean grain size and bringing oxygen vacancies, different Cr2O3 concentrations make the residual voltage ratio increase or decrease accordingly. The lowest residual voltage ratio we obtained is 1.68, when the content of Cr2O3 is 0.03 mol%, which is comparative to commercial ZnO‐based varistor of the same specifications and close to practical use.

Potential Barrier of (Zn,Nb)SnO2‐Films Induced by Microwave Thermal Diffusion of Cr3+ for Low‐Voltage Varistor

“…As noted in the literature,, the increase in the electrical properties is dependent of addition of chromium in the systems. The nonlinear coefficient (α) has a significant improvement and this is related to increase in potential barrier height, since it provides greater blocking the transport of electric current.…”

“…These defects are responsible for the formation of a double barrier for the electrical transport between the grains of SnO 2 in the grain-boundary region. [12][13][14] As noted in the literature, 11,[15][16][17] , the increase in the electrical properties is dependent of addition of chromium in the systems. The nonlinear coefficient (a) has a significant improvement and this is related to increase in potential barrier height, since it provides greater blocking the transport of electric current.…”

Temperature‐ and Atmosphere‐Dependent Defect Chemistry Model of SnO2 Nanocrystalline Film

“…Tin oxide (SnO 2 ) is a relatively inexpensive, chemical stable, and easy to handle material, which is of great interest, as evidenced by a wide number of applications, such as gas sensors, varistors, electrode materials, and solar cells . Undeniably, almost all these applications directly depend on the defect structure and the arising inhomogeneity in SnO 2 .…”