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Sol-Gel Processing of Advanced Dielectric Ceramics for Microwave Applications

Published online by Cambridge University Press:  21 February 2011

M. Schnoeller
Affiliation:
Siemens AG, Corporate Research and Development, Otto-Hahn-Ring 6, D-8000 Munich 83, FRG
W. Wersing
Affiliation:
Siemens AG, Corporate Research and Development, Otto-Hahn-Ring 6, D-8000 Munich 83, FRG
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Abstract

Highly dielectric ceramics make it possible to markedly miniaturize passive microwave components. We have successfully synthesized ceramic powders of the most important microwave ceramic systems (ZrTiSn)O2, Ba(TiNiZnTa)O3 and Ba(MgTa)O3 by using the sol-gel process. Nonaqueous solutions of metal organics together with different inorganic metal salts were used as precursors. The gels derived from these solutions are homogeneous and transparent. Different drying procedures were investigated in order to optimize powder morphology. Thermoanalytic methods and high -temperature x-ray diffraction were used to study the decomposition of xerogels and the formation of crystal phases, respectively. The calcination process was found to be complete at temperatures well below 750 °C.

For the production of barium-containing powders, wet milling must be avoided because this washes out barium and thus causes undesired phases to appear. A dry milling step of the xerogel solves this problem. The prepared (ZrTiSn)O2 and Ba(TiNiZnTa)O3 already equal or surpass the quality of conventionally prepared ceramics.

Type
Research Article
Copyright
Copyright © Materials Research Society 1989

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References

REFERENCES

1. Pöbl, K. and Wolfram, G., Siemens-Components 17, 14 (1982)Google Scholar
2. Wersing, W., to be published in Proc. of the 1989 European Conf. on Electronic Ceramics, London.Google Scholar
3. Wakino, K., Murata, M. and Tamura, H., J. Am. Ceram. Soc. 69, 34 (1986)Google Scholar
4. Wolfram, G. and Göbel, H.E., Mat. Res. Bull. 16, 1455 (1981)Google Scholar
5. Matsumoto, K., Hiuga, T., Tanaka, K. and Ichimura, H., Proc. Of the Sixth IEEE Int. Symp. on Applications of Ferroelectrics (1986) pp. 118121.Google Scholar
6. Phule, P.P. and Risbud, S.H., Adv. Cer. Mat. 3, 183 (1988)Google Scholar