Journal of Materials Science

, Volume 29, Issue 14, pp 3791–3796 | Cite as

Oxidation of ultrafine (Si-) SiC powders

  • R. Vaben
  • D. Stöver


The increasing usage of ultrafine ceramic powders in the fabrication of highly reliable ceramics results in a growing interest in appropriate processing conditions for these powders. During processing the extremely high surface areas might lead to significant absorbtion of oxygen even at low temperatures. But especially in this temperature regime, oxidation data of powders are rarely available; as far as the authors know, no investigations have been published in the case of ultrafine powders with particle sizes below 100 nm. In this study the oxidation kinetics of ultrafine (Si-) SiC powders (∼ 20 nm) in the temperature range between room temperature and 1000 °C in air were investigated. Thermobalance experiments showed that at least three different oxidation mechanisms are operating. At temperature above 650 °C the fraction of completion R is proportional to the square root of time, indicating a diffusion-controlled mechanism (activation energy ∼-1.8 eV). At lower temperatures the best data fit is obtained by a Cabrera-Mott-like equation. At room temperature and for thin silica-layer thicknesses a third oxidation mechanism was determined. The formation of the first monolayer of silicon oxide obeys the kinetics of a first-order reaction, namely an exponential one with a time constant of 1.25× 10−4 s−1. An investigation of the influence of oxygen pressure on the oxidation of ultrafine Si-SiC powders revealed a low pressure influence at 500 °C. An approximately linear relation between pressure and oxidation rate constant is observed between 30 and 1000 mbar air pressure at 800°C. The kinetic data were used to construct an “oxidation map” for ultrafine SiC powders, as a help to determine appropriate processing conditions.


Activation Energy High Surface Area Oxygen Pressure Oxidation Kinetic Oxidation Mechanism 
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  1. 1.
    S. C. Singhal, in “Ceramics for High-Performance Applications”, Proceedings of 2nd Army Materials Technology Conference, Hyannis, Massachusetts, November 1973, edited by J. J. Burke, A. E. Gorom, R. N. Katz (Metals and Ceramics Information Center) p. 533.Google Scholar
  2. 2.
    S. Dutta, J. Mater. Sci. 19 (1984) 1307.CrossRefGoogle Scholar
  3. 3.
    K. L. Luthra, J. Amer. Ceram. Soc. 74 (1991) 1095.CrossRefGoogle Scholar
  4. 4.
    Gmelin Handbook, Silicon, Part B, Section 3, p. 327.Google Scholar
  5. 5.
    F. P. Fehlner, J. Electrochem. Soc.: Solid-State Sci. Technol 119 (1972) 1723.CrossRefGoogle Scholar
  6. 6.
    G. J. Declerck, in Proceedings of NATO Advanced Study Institute on Microelectronic Materials and Processes, Ciocco, Italy, June 1986, edited by R. A. Levy (Klower Academic) p. 79.Google Scholar
  7. 7.
    J. Förster, M. Von Hoesslin, J. H. Schäfer, J. Uhlenbusch and W. Viöl, in Proceedings of 10th International Symposium on Plasma Chemistry, FRG, 1991, Vol. 1, p. 1.Google Scholar
  8. 8.
    P. J. Jorgensen, M. E. Wadsworth and I. B. Cutler, J. Amer. Ceram. Soc. 42 (1959) 613.CrossRefGoogle Scholar
  9. 9.
    R. E. Carter, J. Chem. Phys. 34 (1961) 2010.CrossRefGoogle Scholar
  10. 10.
    K. Motzfeld, Acta Chem. Scand. 18 (1964) 1596.CrossRefGoogle Scholar
  11. 11.
    R. Ebi, thesis, University of Karlsruhe, Germany (1973).Google Scholar
  12. 12.
    R. C. Harris and R. L. Call, in “Silicon Carbide”, edited by R. C. Marshall, J. W. Forest and C. E. Ryan (University of South Carolina Press, Coloumbia, 1973) p. 329.Google Scholar
  13. 13.
    F. P. Fehlner, “Low-Temperature Oxidation” (Wiley, New York, 1986) p. 18.Google Scholar
  14. 14.
    R. Ghez, J. Chem. Phys. 58 (1973) 1838.CrossRefGoogle Scholar
  15. 15.
    F. P. Fehlner, “Low-Temperature Oxidation” (Wiley, New York, 1986) p. 180.Google Scholar
  16. 16.
    R. Lenk, A. F. Kriwostschepow and J. G. Frolow, Chem. Chem. Technol. (in Russian) 54 (148) (1987) 48.Google Scholar
  17. 17.
    F. P. Fehlner, “Low-Temperature Oxidation” (Wiley, New York, 1986) p. 223.Google Scholar

Copyright information

© Chapman & Hall 1994

Authors and Affiliations

  • R. Vaben
    • 1
  • D. Stöver
    • 1
  1. 1.Institut für Werkstoffe der EnergietechnikForschungszentrum Jülich GmbHJülichGermany

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