Journal of Materials Science

, Volume 27, Issue 23, pp 6303–6310 | Cite as

Relationships between dopants, microstructure and the microwave dielectric properties of ZrO2-TiO2-SnO2 ceramics

  • D. M. Iddles
  • A. J. Bell
  • A. J. Moulson
Papers

Abstract

Ceramics with compositions in the solid solution region of the ZrO2-TiO2-SnO2 equilibrium diagram are finding wide application as dielectrics in filters for communications and radar systems operating at microwave frequencies. Commercially available compositions often incorporate sintering aids and dopants to reduce processing temperatures and modify the dielectric properties. However, the mechanism through which these additives influence dielectric loss is not obvious. The role of zinc oxide as a sintering aid and lanthanum and niobium as dopants, their effect upon microstructural development and their correlation with dielectric loss at microwave frequencies were investigated. For specimens of density greater than 90% theoretical, the influences of defect chemistry upon dielectric loss appear to dominate those of the microstructure. Properties close to those which might be considered intrinsic were attained through sintering for periods of up to 128h. Doping with lanthanum is detrimental to the dielectric loss, particularly after long sintering times.

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References

  1. 1.
    J. K. Plourde andChung-Li Ren,IEEE MTT 29 (1981) 754.Google Scholar
  2. 2.
    R. D. Richtmyer,J. Appl. Phys. 10 (1939) 391.Google Scholar
  3. 3.
    R. C. Kell, E. E. Riches, P. Brigginshaw andG. C. E. Olds,Elect. Lett. 6 (1970) 614.Google Scholar
  4. 4.
    R. C. Kell, A. C. Greenham andG. C. E. Olds,J. Amer. Ceram. Soc. 56 (1973) 352.Google Scholar
  5. 5.
    D. J. Masse, R. A. Purcel, D. W. Readey, E. A. Maguire andC. P. Hartwig,Proc. IEEE 59 (1971) 1628.Google Scholar
  6. 6.
    H. M. O'bryan, J. Thomson andJ. K. Plourde,J. Amer. Ceram. Soc. 57 (1974) 450.Google Scholar
  7. 7.
    H. M. O'bryan andJ. Thomson,ibid. 57 (1974) 522.Google Scholar
  8. 8.
    J. K. Plourde, D. F. Linn, H. M. O'bryan andJ. Thomson,ibid. 58 (1975) 418.Google Scholar
  9. 9.
    S. Nomura,Ferroelec. 49 (1983) 61.Google Scholar
  10. 10.
    G. Wolfram andH. E. Gobel,Mater. Res. Bull. 16 (1981) 1455.Google Scholar
  11. 11.
    R. E. Newnham,J. Amer. Ceram. Soc. 50 (1967) 216.Google Scholar
  12. 12.
    K. Wakino, K. Minai andH. Tamura,ibid. 67 (1984) 278.Google Scholar
  13. 13.
    US Pat. 4,785,375 TAM Ceramics, Inc. (1988).Google Scholar
  14. 14.
    JCPDS Reference Cards 34-31 to 34-33.Google Scholar
  15. 15.
    J. C. Wurst andJ. A. Nelson,J. Amer. Ceram. Soc. 55 (1972) 109.Google Scholar
  16. 16.
    M. I. Mendelson,ibid. 52 (1969) 443.Google Scholar
  17. 17.
    B. W. Hakki andP. D. Coleman,IRE Trans. MTT 8 (1960) 402.Google Scholar
  18. 18.
    W. E. Courtney,IEEE Trans. MTT 8 (1970) 476.Google Scholar
  19. 19.
    D. Hennings andP. Schnabel,Philips J. Res. 38 (1983) 295.Google Scholar
  20. 20.
    A. J. Bosman andE. E. Havinga,Phys. Rev. 129 (1963) 1593.Google Scholar
  21. 21.
    D. A. Payne andL. E. Cross, in “Ceramic Microstructures”, edited by R. M. Fulrath and J. A. Pask (Westview Press, Colorado, 1977) p. 548.Google Scholar
  22. 22.
    F. A. Kröger andH. J. Vink, in “Solid State Physics”, Vol. 3, edited by F. Seitz and D. Turnbull (Academic Press, New York, 1981) p. 307.Google Scholar
  23. 23.
    N. H. Chan, R. K. Sharma andD. M. Smyth,J. Amer. Ceram. Soc. 64 (1981) 556.Google Scholar
  24. 24.
    K. Wakino, M. Murata andH. Tamura,ibid. 69 (1986) 34.Google Scholar
  25. 25.
    S. B. Desu andH. M. O'bryan,ibid. 68 (1985) 546.Google Scholar

Copyright information

© Chapman & Hall 1992

Authors and Affiliations

  • D. M. Iddles
    • 1
  • A. J. Bell
    • 1
  • A. J. Moulson
    • 2
  1. 1.Cookson Technology CentreYarntonUK
  2. 2.School of MaterialsUniversity of LeedsLeedsUK

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