Effect of Simultaneous Addition of Zr and Y on Electrical Characteristics of ZnO Varistors
The effect of simultaneously adding Zr and Y to Bi–Mn–Co–Sb–Si–Cr–Ni-added ZnO varistors (having the same composition as a commercial varistor) on the varistor voltage, leakage current, and resistance to electrical degradation were investigated. Varistor voltage increased with increasing amount of Y for addition of 0–2 mol % Zr. On the other hand, the nonlinear coefficient α prior to electrical degradation changed very little on the addition of both Y and Zr. With the addition of approximately 1 mol% Zr, the leakage current decreased with increasing amount of Y added. A ZnO varistor with a varistor voltage of approximately 600 V/m, a low leakage current, and excellent resistance to electrical degradation was fabricated by adding approximately 2 mol% Y and approximately 1 mol% Zr.
Chazono Hirokazu, Fujihara Shinobu, Katayama Keiichi, Masumoto Hiroshi, Mizoguchi Teruyasu, Osada Minoru, Shinozaki Kazuo and Takeda Hiroaki
T. Watanabe et al., "Effect of Simultaneous Addition of Zr and Y on Electrical Characteristics of ZnO Varistors", Key Engineering Materials, Vol. 485, pp. 257-260, 2011