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Journal of Materials
Volume 2013 (2013), Article ID 726314, 5 pages
Research Article

Preparation of Ultrahigh Potential Gradient of ZnO Varistors by Rare-Earth Doping and Low-Temperature Sintering

1Department of Mathematics and Physics, Shanghai Dianji University, Shanghai 201306, China
2World Premier International Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, Ibaraki 305-0044, Japan
3State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China

Received 9 December 2012; Accepted 4 January 2013

Academic Editor: Pawan K. Kahol

Copyright © 2013 Lei Ke et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The effects of rare-earth doping and low-temperature sintering on electrical properties of ZnO varistors were investigated. The potential gradient of the ZnO varistors increased significantly to 2247.2 V/mm after doping 0.08 mol% of Y2O3 and sintering at 800°C for 2 h. The notable decrease of the grain size with the given experimental conditions was the origin for the increase in . During the process of high-temperature sintering, both the oxygen at the grain boundary interface and the neutralisation of the ions on the depletion layer were directly reduced, which caused the weight loss and the internal derangement of double Schottky barriers.