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High-Temperature Dielectric Properties of Polycrystalline Ceramics

Published online by Cambridge University Press:  21 February 2011

W. W. Ho
W. W. Ho*
Affiliation:
Rockwell International Science Center, 1049 Camino Dos Rios, Thousand Oaks, CA 91360
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Abstract

Experimental methods for determining the high-temperature millimeter-wave dielectric properties of solids are described and the data obtained on a wide variety of polycrystalline ceramics are reviewed. In general, the observed increase in dielectric constants with temperature can be modeled with a macroscopic dielectric virial expansion and shown to be primarily caused by an increase in polarizability due to volume expansion. The room-temperature loss tangents in low-absorption ceramics are probably caused by impurity doping of the primary and secondary crystalline phases at grain junctions and along grain boundaries. The rapid increase in loss tangent at high temperatures commonly observed in polycrystalline ceramics is associated with softening of intergranular amorphous phases resulting in an increase in localized electrical conductivity.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 124: Symposium M – Microwave Processing of Materials I , 1988 , 137
Copyright
Copyright © Materials Research Society 1988

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References

REFERENCES

1. Von Hippel, A., Dielectric Materials and Applications, edited by Von Hippel, A. (Technology Press of MIT and John Wiley & Sons, New York, 1954), pp. 291–429.Google Scholar
2. Westphal, W.B. and Sils, A., Dielectric Constant and Loss Data, Technical AFMLTR-72-39, Air Force Materials Laboratory, Wright-Patterson AFB, April, 1972.Google Scholar
3. Westphal, W.B., Dielectric Constant and Loss Data, Technical Report AFML-TR-74-250, Part II (December 1975), Part III (May 1977), Part IV (December 1980), Air Force Materials Laboratory, Wright-Patterson AFB.CrossRefGoogle Scholar
4. Fuller, J.A., Taylor, T.S., Elfe, T.B., and Hill, G.N., Dielectric Properties of Ceramics for Millimeter-Wave Tubes, Technical Report AFWAL-TR-84-1005, Air Force Avionics Laboratory, Wright-Patterson AFB, February 1984.Google Scholar
5. Ho, W., High Temperature Millimeter-Wave Characterization of the Dielectric Properties of Advanced Window Materials, Final Report, TR82-28, Army Material and Mechanic Research Center, May 1982; Millimeter-Wave Dielectric Property Measurement of Gyrotron Window Materials, Technical Report ORNL/SUB-83-519261/1 (April 1984), ORNL/SUB-83-51 926/2 (April 1985), Oak Ridge National Laboratory; High Temperature Dielectric Property Testing of Sensor Window Materials, Final Report, N60921-81-C-0295, Naval Surface Warfare Center, MAY 1986; Characterization of Dielectric Properties of Candidate Antenna Window Materials, Final Report, DAAG46-82-C-0022, Army Material and Mechanic Research Center, October 1987.Google Scholar
6. Bosman, A.J. and Havinga, E.E., Phys. Rev. 129, 1593 (1963).Google Scholar
7. Afsar, M.N. and Button, K.J., Digest of Millimeter and Submillimeter Wave Materials Information and Measurements, MIT Francis Bitter National Magnet Laboratory, (1983).Google Scholar
8. Slack, G.A., General Electric Technical Information Series Report TIS78-SDR- 2199, May 15, 1978.Google Scholar
9. Ho, W. and Harker, A.B., Proc. 1st DoD Electromagnetic Window Symposium, MP85-148 1, 2–6, Naval Surface Warfare Center (1985).Google Scholar
10. Morgan, P.E.D. and Koutsoutis, M.S., J. Am. Ceram. Soc. 69[10], C–254 (1986).Google Scholar
11. Ho, W.W. and Morgan, P.E.D., J. Am. Ceram. Soc. 70[9], C–209 (1987).Google Scholar