Influence of Ca-doping on the nonlinear properties of novel ZnO-Cr2O3-based varistor ceramics

The influence of Ca-doping on the microstructure development and electrical characteristics was studied in the novel, ZnO-Cr2O3-based, varistor ceramics with the nominal composition (99.47-x) mol% ZnO + 0.1 mol% Cr2O3 + 0.33 mol% Co3O4 + 0.1 mol% La2O3 + x mol% CaCO3, with x ranging from 0 to 6, sin...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the European Ceramic Society 2022-05, Vol.42 (5), p.2268-2273
Main Authors: Tian, Tian, Zheng, Liaoying, Podlogar, Mateja, Man, Zhenyong, Ruan, Xuezheng, Shi, Xue, Bernik, Slavko, Li, Guorong
Format: Article
Language:English
Subjects:
Ca-doping
Electrical properties
Microstructure
Varistor ceramics
Zinc oxide
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The influence of Ca-doping on the microstructure development and electrical characteristics was studied in the novel, ZnO-Cr2O3-based, varistor ceramics with the nominal composition (99.47-x) mol% ZnO + 0.1 mol% Cr2O3 + 0.33 mol% Co3O4 + 0.1 mol% La2O3 + x mol% CaCO3, with x ranging from 0 to 6, sintered at 1200 °C. The results showed that, within the limits of the solid solubility of CaO in ZnO, the addition of CaO greatly enhanced the diffusion processes and hence the grain growth, thus broaden the range of breakdown voltages. Moreover, the Ca-doping simultaneously increases the height of the electrostatic Schottky barrier, resulting in a higher nonlinear coefficient of 40 and a lower leakage current of 2.8 μA/cm2. The results are important for the potential application of these novel ZnO-Cr2O3-based varistors, having different nominal voltages and yet suitable dimensions, in overvoltage protection across a broad range of voltages.
ISSN:0955-2219
1873-619X
DOI:10.1016/j.jeurceramsoc.2021.12.064