Improved current limiters based on mixed-phase BaTiO3 ceramic semiconductors

  • T. R. N. Kutty
  • V. Ravi
Papers

Abstract

Very stable and highly reproducible current-limiting characteristics have been observed for polycrystalline ceramics prepared from sintering mixtures of coarse-grained, donor-doped BaTiO3 (tetragonal) as the major phase and ultrafine, undoped cubic perovskite such as BaSnO3, BaZrO3, SrTiO3 or BaTiO3 (cubic) as the minor phase. The initial linear current-voltage (I-V) relationship becomes current-limiting with increase in applied potential and the consequent onset of thermal equilibrium. The strong current maximum of theI-V curve of donor-doped BaTiO3 can be eliminated when the ceramics are constituted of mixed phases. The voltage drop at the insulating grain boundaries minimizes the temperature gradient between the interior and the surface, and subdues the thermal runaway. The magnitude of the limiting current, and hence the power-handling capacity, can be varied with the controlled addition of grain boundary layer modifiers and by optimizing the processing parameters. The dielectric constant versus temperature or voltage variation in power dissipation with ambient temperature and resistivity-temperature relations point to the necessity of the mixed phase character for the current-limiting property.

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References

  1. 1.
    O. SABURI and K. WAKINO,IEEE Trans. Component Parts 10 (1963) 53.Google Scholar
  2. 2.
    T. KRELLNER,Elec. Design 23 (1977) 76.Google Scholar
  3. 3.
    Y. TING,IEEE Trans. Indust. Applics 8 (1972) 338.Google Scholar
  4. 4.
    H. S. GOPALAKRISHNAMURTHY, M. SUBBARAO and T. R. N. KUTTY,J. Inorg. Nucl. Chem. 37 (1975) 891.Google Scholar
  5. 5.
    M. AVUDAITHAI and T. R. N. KUTTY,Mater. Res. Bull. 22 (1987) 641.Google Scholar
  6. 6.
    R. VIVEKANANDAN and T. R. N. KUTTY,Ceram. Int. 14 (1988) 207.Google Scholar
  7. 7.
    R. VIVEKANANDAN, S. PHILIP and T. R. N. KUTTY,Mater. Res. Bull. 22 (1987) 99.Google Scholar
  8. 8.
    R. VIVEKANANDAN and T. R. N. KUTTY,Powder Technol. 57 (1989) 181.Google Scholar
  9. 9.
    Y. MATSUO and H. SASAKI,J. Amer. Ceram. Soc. 54 (1971) 471.Google Scholar
  10. 10.
    N. S. GAJBHIYE and T. R. N. KUTTY,Bull. Electrochem. Soc. 2 (1986) 231.Google Scholar
  11. 11.
    P. MURAGARAJ and T. R. N. KUTTY,Mater. Res. Bull. 20 (1985) 1473.Google Scholar
  12. 12.
    P. MURAGARAJ, T. R. N. KUTTY and M. SUBBARAO,J. Mater. Sci. 21 (1986) 3521.Google Scholar
  13. 13.
    T. R. N. KUTTY and P. MURAGARAJ,Mater. Res. Bull. 20 (1985) 565.Google Scholar
  14. 14.
    R. VIVEKANANDAN and T. R. N. KUTTY,Mater. Sci. Engng B6 (1990) 221.Google Scholar
  15. 15.
    N. YAMAOKA, M. MASUYAMA and M. FUKUI,Ceram. Bull. 62 (1983) 698.Google Scholar
  16. 16.
    N. YAMAOKA, ibid.65 (1986) 1149.Google Scholar
  17. 17.
    L. M. LEVINSON, ibid.68 (1989) 866.Google Scholar
  18. 18.
    G. A. SMOLENSKY,J. Phys. Soc. Jpn. 28 (Suppl.) (1970) 26.Google Scholar
  19. 19.
    D. HENNINGS, A. SCHNELL and G. SIMON,J. Amer. Ceram. Soc. 65 (1982) 539.Google Scholar
  20. 20.
    T. R. N. KUTTY, L. GOMATHI DEVI and P. MURAGARAJ,Mater. Res. Bull. 21 (1986) 1093.Google Scholar
  21. 21.
    T. R. N. KUTTY,Proc. Indian Acad. Sci. 96 (1986) 581.Google Scholar
  22. 22.
    G. V. LEWIS, C. R. A. CATLOW and R. E. W. CASSELTON,J. Amer. Ceram. Soc. 68 (1985) 555.Google Scholar
  23. 23.
    T. R. N. KUTTY, P. MURAGARAJ and N. S. GAJBHIYE,Mater. Lett. 2 (1984) 391.Google Scholar
  24. 24.
    T. R. N. KUTTY and L. GOMATHI DEVI,Mater. Res. Bull. 20 (1985) 793.Google Scholar
  25. 25.
    J. DANIELS and R. WERNICKE,Philips Res. Rep. 31 (1976) 544.Google Scholar
  26. 26.
    R. WERNICKE, ibid.31 (1976) 526.Google Scholar

Copyright information

© Chapman and Hall Ltd 1991

Authors and Affiliations

  • T. R. N. Kutty
    • 1
  • V. Ravi
    • 1
  1. 1.Materials Research CentreIndian Institute of ScienceBangaloreIndia

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