Abstract

The microstructure and electrical properties of ternary system ZnO–0.5 mol% V₂O₅–MnO₂ ceramics sintered were investigated in accordance with MnO₂ content by sintering at 900 °C. For all samples, the microstructure of the ternary system ZnO–V₂O₅–MnO₂ ceramics consisted of mainly ZnO grain and secondary phase Zn₃(VO₄)₂. The incorporation of MnO₂ to the binary system ZnO–V₂O₅ ceramics was found to restrict the abnormal grain growth of ZnO. The breakdown field in the E–J characteristics increased from 175 to 992 V/cm with the increase of MnO₂ content. The incorporation of MnO₂ improved non-ohmic properties by increasing non-ohmic coefficient. The highest non-ohmic coefficient (27.2) in the ternary system ZnO–0.5 mol% V₂O₅–MnO₂ was obtained for MnO₂ content of 2.0 mol%.

Keywords: Ternary system ZnO–V₂O₅–MnO₂; Electrical properties; Varistor ceramics

Article Outline

1. Introduction

2. Experimental procedure

2.1. Sample preparation

2.2. Microstructure measurement

2.3. Electrical measurement

3. Results and discussion

4. Conclusions

References