Advertisement

Journal of Materials Science

, Volume 24, Issue 5, pp 1819–1826 | Cite as

Electrical properties of carbon-doped KNO3 thin layers

  • F. El-Kabbany
  • S. Taha
  • E. H. El-Khawas
Papers

Abstract

A series of carbon-doped KNO3 thin layers was grown from the melt by a special technique. The changes of the dielectric constant, d.c. resistivity, energy of vacancy formation, pyroelectric current and ferroelectric hysteresis loops with carbon concentration were investigated. The present study aims to clarify the effect of doping carbon as a conducting material on the properties of the dielectric KNO3 thin layers by extensive use of experimental data from isomorphous sets of solid solutions of carbon and KNO3. These systems were studied in the vicinity of the order-disorder phase transition region for various values of carbon concentrationx betweenx=0 andx=0.08. For the carbon doped layers, large changes in the electrical properties were found depending on the doped carbon concentration. The dielectric constant and d.c. resistivity were reduced appreciably, while the pyroelectric current showed improved behaviour in the presence of carbon, as compared with pure KNO3 thin layers. Anomalous ferroelectric hysteresis loops were obtained in carbon-doped layers with a reduction of the ferroelectric loop temperature region by ca. 10° C at carbon concentrationx=0.07. The ferroelectric loops of the carbon-doped layers could be obtained <x = 0.07 with little loop deformation. The results showed that the carbon doping process delayed the phase transition point by 5 to 6° C forx=0.06. Also, the energy of vacancy formation showed its minimum value of 0.45 eV atx=0.03 to 0.04. The marked change in the detailed character of the different electric properties of the doped layers during phase transition in the presence of carbon was interesting.

Keywords

Phase Transition Dielectric Constant Carbon Concentration KNO3 Vacancy Formation 
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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    E. Rapoport andG. C. Kennedy,J. Phys. Chem. Solids 26 (1965) 1995.Google Scholar
  2. 2.
    P. W. Bridgeman,Proc. Amer. Acad. Arts. Sci. 51 (1916) 582.Google Scholar
  3. 3.
    A. Kodyashi, Z. Oda, S. Kawaji, H. Arata andK. Sugujama,J. Phys. Chem. Solids 14 (1960) 37.Google Scholar
  4. 4.
    C. S. Hung andJ. R. Gliesman,Phys. Rev. 99 (1955) 406.Google Scholar
  5. 5.
    B. Read, D. Weinreich andH. F. Matare,Phys. Rev. 113 (1959) 454.Google Scholar
  6. 6.
    C. A. Hampel, “The Encyclopedia of the Chemical Elements” (Reinhold Book Corporation, New York, 1968).Google Scholar
  7. 7.
    T. Hammad, F. El-Kabbany andY. Badr,Phys. Stat. Solidi(a) 94 (1986) 121.Google Scholar
  8. 8.
    F. El-Kabbany, W. Badaway, N. H. Tahr andE. H. El-Khwas,Ferroelectrics under publication, 1987.Google Scholar
  9. 9.
    C. V. Raynor, “Structure of metals and Alloys”, (The Institute of Metals, London, 1954).Google Scholar
  10. 10.
    K. Meyer,Metallurgiya,196 (1972) 38.Google Scholar
  11. 11.
    E. A. Moelwyn-Hughes,J. Izd. Inost. Lit 1 (1962) 492.Google Scholar
  12. 12.
    B. V. Nekrasov,Izd. Khimiya 3 (1970) 26.Google Scholar
  13. 13.
    W. L. Buck andL. W. Stock,Am. Mineral 40 (1955) 192.Google Scholar
  14. 14.
    T. Baars andJ. Brand,J. Phys. Chem. Solids 34 (1973) 5.Google Scholar
  15. 15.
    S. K. Filatov,Uch. Zap. LGU, Ser. Geol Nauk,14 (1973).Google Scholar
  16. 16.
    A. Maradudin andA. Berander,J. Phys. Redium 24 (1963) 89.Google Scholar
  17. 17.
    M. L. Kite andO. F. Tuttle,Izd. Inost. Lit (1954) 215.Google Scholar
  18. 18.
    M. J. Yacaman andA. G. Bassett,Thin Solid Films (1976) 35.Google Scholar

Copyright information

© Chapman and Hall Ltd. 1989

Authors and Affiliations

  • F. El-Kabbany
    • 1
  • S. Taha
    • 1
  • E. H. El-Khawas
    • 1
  1. 1.Physics Department, Faculty of ScienceCairo UniversityCairoEgypt

Personalised recommendations