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Journal of Materials Science

, Volume 26, Issue 4, pp 1126–1130 | Cite as

Electrical characteristics and reheat-treatment effects in a ZnO varistor fabricated by two-stage heat-treatment

  • N. Y. Lee
  • M. -S. Kim
  • I. -J. Chung
  • M. -H. Oh
Papers

Abstract

Conventional ZnO varistors are generally fabricated by sintering ZnO powder mixed with additives such as Bi2O3, Sb2O3, Cr2O3, Co2O3, and MnO2. To reduce abnormal grain growth and change in electrical characteristics in the conventional ZnO varistors caused by volatilization of Bi2O3, the ZnO powder with all additive oxides except Bi2O3 was pressed into disc form and sintered. The disc was then painted with metal oxide paste containing Bi2O3 and again fired. The ZnO varistor fabricated by this process, i.e. a two-stage heat-treatment process, showed typical non-linearI-V characteristics with higher breakdown voltage exceeding 800 V mm−1. It was also observed that the non-linearI-V coefficient change rate, Δα, in the ZnO varistor due to reheat-treatment is almost linearly proportional to the sintered density.

Keywords

Oxide Metal Oxide MnO2 Change Rate Co2O3 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    L. M. Levinson andJ. R. Philipp,J. Appt. Phys. 46 (1975) 1332.CrossRefGoogle Scholar
  2. 2.
    J. Wong,ibid. 46 (1975) 1653.CrossRefGoogle Scholar
  3. 3.
    K. Eda,ibid. 49 (1978) 2964.CrossRefGoogle Scholar
  4. 4.
    A. Kusy andT. G. M. Kleinpenning,ibid. 54 (1983) 2900.CrossRefGoogle Scholar
  5. 5.
    E. D. Kim, C. H. Kim andM. H. Oh,ibid. 58 (1985) 3231.CrossRefGoogle Scholar
  6. 6.
    M. Inada,Jpn J. Appl. Phys. 19 (1980) 409.CrossRefGoogle Scholar
  7. 7.
    T. Takemura, M. Kobayashi, Y. Takada andK. Sato,J. Amer. Ceram. Soc. 70 (1987) 237.CrossRefGoogle Scholar
  8. 8.
    H. Kanai andM. Imai,J. Mater. Sci. 23 (1988) 4379.CrossRefGoogle Scholar
  9. 9.
    J. Wong andW. G. Morris,Ceram. Bull. 53 (1974) 816.Google Scholar
  10. 10.
    Randall M. German, “Liquid Phase Sintering” (Plenum Press, New York, 1985) Ch. 6.CrossRefGoogle Scholar
  11. 11.
    M. Inada,Jpn J. Appl. Phys. 18 (1979) 1439.CrossRefGoogle Scholar
  12. 12.
    J. W. Medernich andR. L. Snyder,J. Amer. Ceram. Soc. 61 (1978) 494.CrossRefGoogle Scholar
  13. 13.
    T. Takemura, M. Kobayashi, Y. Takada andK. Sato,ibid. 69 (1986) 430.CrossRefGoogle Scholar
  14. 14.
    M. Inada,Jpn J. Appl. Phys. 17 (1978) 1.CrossRefGoogle Scholar
  15. 15.
    M. Matsuoka,ibid. 10 (1971) 736.CrossRefGoogle Scholar

Copyright information

© Chapman and Hall Ltd 1991

Authors and Affiliations

  • N. Y. Lee
    • 1
  • M. -S. Kim
    • 1
  • I. -J. Chung
    • 1
  • M. -H. Oh
    • 1
  1. 1.Korea Institute of Science and TechnologyCheongryang, SeoulKorea

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