Publisher : The Korean Institute of Electrical and Electronic Material Engineers
DOI : 10.4313/TEEM.2015.16.4.221
Title & Authors
Microstructure and Varistor Properties of ZVMND Ceramics with Sintering Temperature Nahm, Choon-Woo;
The sintering effect on the microstructure, electrical properties, and dielectric characteristics of ZnO-V2O5-MnO2-Nb2O5-Dy2O3-based ceramics was investigated. With the increase of sintering temperature from 875 to 950℃, the density of the sintered pellets decreased from 5.57 to 5.45 g/cm3 and the average grain size increased from 4.3 to 10.9 μm. The breakdown field decreased noticeably from 6,095 to 996 V/cm with the increase of sintering temperature. The varistor ceramics sintered at 900℃ exhibited the best nonlinear properties: 39.2 in the nonlinear coefficient and 0.24 mA/cm2 in the leakage current density. The dielectric constant increased sharply from 658.6 to 2,928.8 with the increase of sintering temperature. On the whole, the dissipation factor exhibited a fluctuation with the increase of the sintering temperature, and a minimum value of 0.284 at 900℃.