%0 Journal Article
%T Microstructure and Electrical Properties of ZPCCYT Varistor Ceramics
%A Choon-Woo Nahm
%A Sun-Kwon Lee
%J Transactions on Electrical and Electronic Materials
%D 2012
%I Korean Institute of Electrical and Electronic Material Engineers (KIEEME)
%X The Microstructure and nonlinear electrical properties of the ZPCCYT (ZnO-Pr6O11-CoO-Cr2O3-Y2O3-Tb4O7) varistorswere investigated for different amounts of Tb4O7. The addition of Tb4O7 has a significant effect on microstructureand electrical properties. Analysis of the microstructure indicated that the ceramics consisted of ZnO grain as a mainphase and a few secondary phases as a mix of Pr6O11, Y2O3, and Tb4O7. As the amount of Tb4O7 increased, the sintereddensities of pellets increased from ¦Ñ = 5.70 to 5.78 g/cm3 and the average grain size decreased from d = 4.8 to 3.6 ¦Ìm.The increase in the amount of Tb4O7 increased from EB = 7,473 to 10,035 V/cm and from ¦Á = 39.7 to 52.2. In particular,it was found that the ceramics modified with 1.0 mol% in the amount of Tb4O7 are suited for the varistors for highvoltage in the light of a high sintered density and a high voltage gradient.
%K Tb4O7
%K ZnO-Pr6O11-Based ceramics
%K Breakdown field
%K Varistors
%U http://dx.doi.org/10.4313/TEEM.2012.13.5.262