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Journal of Materials Science

, Volume 29, Issue 10, pp 2691–2696 | Cite as

Grain size effects on the dielectric properties of ferroelectric Bi2VO5.5 ceramics

  • K. V. R. Prasad
  • A. R. Raju
  • K. B. R. Varma
Papers

Abstract

Dielectric properties and microstructural characteristics of ferroelectric bismuth vanadate (Bi2VO5.5) ceramics exhibiting grain sizes of 7, 10, 20 and 25 μm have been studied. Microstructural studies indicate the presence of ferroelectric 90° domain patterns on the surface as well as in the bulk of the coarse-grained ceramics. The dielectric constant and the loss tangent both at room temperature and in the vicinity of the Curie temperature have been found to increase with increasing grain size. The Curie temperature (725 K) is found to shift slightly (by about 7 K) towards higher temperatures as the grain size increases (7–25 μm). The magnitude of the dielectric anomaly around 725 K is found to be higher for coarse-grained ceramics. The dielectric constant and the loss have been found to decrease with increase in frequency (1–100 kHz) for all the ceramics studied. The increase in dielectric constant with increasing grain size is attributed to a decrease in thickness of the relatively more insulating grain boundary layer.

Keywords

Polymer Grain Size Boundary Layer Dielectric Constant Vanadate 
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.
    V. G. Osipyan, L. M. Savchenko, V. L. Elbakyan and P. B. Avakyan, Russ. J. Inorg. Mater. 23 (1987) 467.Google Scholar
  2. 2.
    V. N. Borisov, Yu. M. Poplavko, P. B. Avakyan and V. G. Osipyan, Sow. Phys. Solid State 30 (1988) 904.Google Scholar
  3. 3.
    A. A. Bush and Yu. N. Venevtsev, Russ. J. Inorg. Chem. 31 (1986) 769.Google Scholar
  4. 4.
    K. B. R. Varma, G. N. Subbanna, T. N. Guru Row and C. N. R. Rao, J. Mater. Res. 5 (1990) 2718.CrossRefGoogle Scholar
  5. 5.
    K. V. R. Prasad and K. B. R. Varma, J. Phys. D: Appl. Phys. 24 (1991) 1858.CrossRefGoogle Scholar
  6. 6.
    K. V. R. Prasad and K. B. R. Varma, (to be published).Google Scholar
  7. 7.
    F. Abraham, M. F. Debreuille-Gresse, G. Mairesse and G. Nowogrocki, Solid State Ion. 28–30 (1988) 529.CrossRefGoogle Scholar
  8. 8.
    W. D. Kingery, H. K. Bowen and D. R. Uhlmann, “Introduction to Ceramics” (John Wiley, New York, 1976).Google Scholar
  9. 9.
    J. Paletto, G. Grange, R. Goutte and L. Eyraud, J. Phys. D: Appl. Phys. 7 (1974) 78.CrossRefGoogle Scholar
  10. 10.
    H. T. Martirena and J. C. Burfoot, J. Phys. C 7 (1974) 3182.CrossRefGoogle Scholar
  11. 11.
    G. Samara, “Advances in High-pressure Research” (Academic Press, New York, 1969).Google Scholar

Copyright information

© Chapman & Hall 1994

Authors and Affiliations

  • K. V. R. Prasad
    • 1
  • A. R. Raju
    • 1
  • K. B. R. Varma
    • 1
  1. 1.Materials Research CentreIndian Institute of ScienceBangaloreIndia

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