Electrical Properties and Microstructure of ZnO-Nb2O5-MnO Ceramics Sintered in the Liquid Phase

  • Kenya Hamano
  • Zenbe-e Nakagawa
  • Yoshiaki Okamoto
  • Akio Sayano
  • Tatsuro Mitsudome
Part of the Materials Science Research book series (MSR, volume 21)

Abstract

Effect of several additives to ZnO-Nb205-MnO system on varistor characteristics were investigated. BaO and Si02 improved the varistor characteristics, but Co0 decreased the nonlinear exponent. The specimens with Si02 fired below the eutectic temperature also showed the nonlinear characteristics. The concentration difference of some components between the ZnO grains and the intergranular phases, and the temperature dependence of these distribution coefficients are essential for the appearance of varistor characteristics. Liquid phase sintering and high wettability are very convenient to elevate the characteristics. The addition of CeO2 markedly decreased the electrical resistivity and did not show the nonlinear characteristic. The addition of Pr6011 did not change the electrical properties but improved the stability of current.

Keywords

Zinc Shrinkage Bismuth Wettability Praseodymium 

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Copyright information

© Plenum Press, New York 1987

Authors and Affiliations

  • Kenya Hamano
    • 1
    • 2
  • Zenbe-e Nakagawa
    • 1
  • Yoshiaki Okamoto
    • 1
  • Akio Sayano
    • 1
  • Tatsuro Mitsudome
    • 1
  1. 1.Research Laboratory of Engineering MaterialsTokyo Institute of TechnologyNagatsuta Midori-ku, Yokohama-shi 227Japan
  2. 2.Kanagawa UniversityJapan

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