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Temperature-stable microwave dielectric ceramics in the Ca5A2Ti1-xZrxO12 (A = Nb, Ta) system

Published online by Cambridge University Press:  01 October 2004

Pazhoor Varghese Bijumon  and
Mailadil Thomas Sebastian
Pazhoor Varghese Bijumon
Affiliation:
Ceramic Technology Division, Regional Research Laboratory, Trivandrum 695 019, India
Mailadil Thomas Sebastian*
Affiliation:
Ceramic Technology Division, Regional Research Laboratory, Trivandrum 695 019, India
*
a)Address all correspondence to this author. e-mail: mailadils@yahoo.com
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Abstract

Ca5A2Ti1−xZrxO12 (A = Nb, Ta) ceramics were prepared through conventional solid-state ceramic route for 0 ⩽ x ⩽ 1. The crystal structures of the ceramics were studied by x-ray diffraction techniques, and dielectric properties were measured at microwave frequencies. In the Ca5Nb2Ti1−xZrxO12 system as x increases from 0 to 1, ϵr decreases from 48 to 25, Qu× f from 26,000 to 19,000 GHz, and τf from +40 to −21 ppm/°C. In Ca5Ta2Ti1−xZrxO12 ceramics, ϵr varies from 38 to 22, Quxf from 33,000 to 24,000 GHz, and τf from +10 to −26 ppm/°C as x is changed from 0 to 1. The variation of microwave dielectric properties with bond valence and electronegativity in the two systems were also investigated. Ca5Nb2Ti0.2Zr0.8O12 and Ca5Ta2Ti0.7Zr0.3O12 dielectric ceramics were found to have stable resonant frequency with temperature and are potential candidates for applications in personal and satellite communication systems in the S and C band (2–8 GHz).

Keywords

CeramicSinteringDielectric properties
Type
Articles
Information
Journal of Materials Research , Volume 19 , Issue 10 , October 2004 , pp. 2922 - 2928
Copyright
Copyright © Materials Research Society 2004

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References

REFERENCES

1Wersing, W. High frequency ceramic dielectrics and their applications for microwave components. In Electronic Ceramics, edited by Steele, B.C.H. (Elsevier, New York, 1991), p. 67Google Scholar
2Davies, P.K. Materials and process for wireless Communication. In Ceramic Transactions, Vol. 53, edited by Negas, T. and Ling, H. (Am. Ceram. Soc., Westerville, OH, 1995), p. 137Google Scholar
3Negas, T., Yeager, G., Bell, S. and Amren, R. Chemistry of Electronic Ceramic Materials. In NIST special publication vol. 804, edited by Davies, P.K. and Roth, R.S. (Technomic Publishing Inc., Lancaster, PA, 1990), p. 21Google Scholar
4Nomura, S., Toyama, K. and Kaneta, K.: Ba(Mg1/3Ta2/3)O3 ceramics with temperature stable high-dielectric constant and low microwave loss. Jpn. J. Appl. Phys. 21, 624 (1982).CrossRefGoogle Scholar
5Kawashima, Y., Nishida, M., Ueda, J. and Ouchi, H.: Ba(Mg1/3Ta2/3)O3 ceramics with low-dielectric loss at microwave frequencies. J. Am. Ceram. Soc. 66, 421 (1983).CrossRefGoogle Scholar
6Cava, R.J., Krajewski, J.J. and Roth, R.S.: Ca5Nb2TiO12 and Ca5Ta2TiO12: Low temperature coeficient low loss dielectric materials. Mater. Res. Bull. 34, 355 (1999).CrossRefGoogle Scholar
7Bendersky, L.A., Krajewski, J.J. and Cava, R.J.: Dilelectric properties and microstructure of Ca5Nb2TiO12 and Ca5Ta2TiO12. J. Eur. Ceram. Soc. 21, 2653 (2001).CrossRefGoogle Scholar
8Cava, R.J. and Krajewski, J.J.: Stabilization of the temperature coefficient of dielectric constant of Ca5Nb2TiO12 by Zr doping. Mater. Res. Bull. 34, 1817 (1999).CrossRefGoogle Scholar
9Bijumon, P.V., Mohanan, P. and Sebastian, M.T.: Synthesis, characterization and properties of Ca5A2TiO12 (A=Nb, Ta) ceramic dielectric materials for applications in microwave telecommunication systems. Jpn. J. Appl. Phys. 41, 3384 (2002).CrossRefGoogle Scholar
10Bijumon, P.V., Mohanan, P. and Sebastian, M.T.: High-dielectric constant low loss microwave dielectric ceramics in the Ca5Nb2-xTaxTiO12 system. Mater. Lett. 57, 1380 (2003).CrossRefGoogle Scholar
11Bijumon, P.V., Sreedevi, X., Menon, K., Mohanan, P. and Sebastian, M.T.: Enhanced bandwidth microstrip patch antennas loaded with high permittivity dielectric resonators. Micro. Opt. Tech. Lett. 35, 327 (2002).CrossRefGoogle Scholar
12Sreemoolanadhan, H., Issac, J., Sebastian, M.T., Jose, K.A. and Mohanan, P.: Synthesis, characterization and properties of Ba1-xSrx(Nd0.5Nb0.5)O3 ceramics for application as dielectric resonator in microwave circuits. Ceram. Int. 21, 385 (1995).CrossRefGoogle Scholar
13Sebastian, M.T., Santha, N., Bijumon, P.V., Axelsson, Anna-Karin and Alford, N. McN.: Microwave dielectric properties of (1-x)CeO2 – xCaTiO3 and (1-x)CeO2 – xSm2O3 ceramics. J. Eur. Ceram. Soc. 24, 2583 (2004).CrossRefGoogle Scholar
14Surendran, K.P., Varma, M.R., Mohanan, P. and Sebastian, M.T.: Microwave dielectric properties of [RE′1-xRE′x]TiNbO6 (RE′= Pr, Nd, Sm; RE′ = Gd, Dy, Y) dielectric ceramics. J. Am. Ceram. Soc. 86, 1695 (2003).CrossRefGoogle Scholar
15Ohsato, H.: Science of tungsten bronze-type like Ba6-3xR8+2xTi18O54 (R = Rare earth) microwave dielectric solid solutions. J. Eur. Ceram. Soc. 21, 2703 (2001).CrossRefGoogle Scholar
16Zhang, S.X., Li, J.B., Cao, J., Zhai, H.Z. and Zhang, B.: Preparation, microstructure and microwave dielectric properties of ZrxTi1-xO4 (x = 0.40 – 0.60) ceramics. J. Eur. Ceram. Soc. 21, 2931 (2001).CrossRefGoogle Scholar
17Hakki, B.W. and Coleman, P.D.: A dielectric resonator method of measuring inductive capacitance in the millimeter range. IRE Trans. Microwave Theory Tech. MTT–8, 402 (1960).CrossRefGoogle Scholar
18Courtney, W.E.: Analysis and evaluation of a method of measuring the complex permittivity and permeability of microwave insulators. IEEE Trans. Microw. Theory Tech. MTT–18, 476 (1970).CrossRefGoogle Scholar
19Krupka, J., Derzakowski, K., Riddle, B. and Jarvis, J.B.: A dielectric resonator for measurements of complex permittivity of low loss dielectric materials as function of temperature. Meas. Sci. Technol. 9, 1751 (1998).CrossRefGoogle Scholar
20Brese, N.E. and O’Keefe, M.: Bond-valence parameters for solids. Acta Crystallogr. B 47, 192 (1991).CrossRefGoogle Scholar
21Park, H.S., Yoon, K.H. and Kim, E.S.: Effect of bond valence on microwave dielectric properties of complex perovskite ceramics. Mater. Chem. Phys. 79, 181 (2003).CrossRefGoogle Scholar
22Kim, E.S., Kim, Y.H., Chae, J.H., Kim, D.W. and Yoon, K.H.: Dielectric properties of [(Pb0.2Ca0.8)1-xSrx](Ca1/3Nb2/3)O3 ceramics at microwave frequencies. Mater. Chem. Phys. 79, 230 (2003).CrossRefGoogle Scholar
23Kim, E.S., Kim, Y.H., Chun, B.S., Kim, Y.T. and Yoon, K.H.: Effect of Ti4+ substitution on microwave dielectric properties of (Pb0.2Ca0.8)[(Ca1/3Nb2/3)1-xTix]O3 ceramics. Mater. Chem. Phys. 79, 233 (2003).CrossRefGoogle Scholar
24Brown, I.D. and Altermatt, D.: Bond-valence parameters obtained from a systematic analysis of the inorganic crystal structure database. Acta Crystallogr. B 41, 244 (1985).CrossRefGoogle Scholar
25Shannon, R.D.: Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallogr. A 32, 751 (1976).CrossRefGoogle Scholar
26Roth, R.S.: Classification of perovskite and other ABO3 – type compounds. J. Res. Natl. Bur. Stand. 58, 75 (1957).CrossRefGoogle Scholar
27Shannon, R.D.: Dielectric polarisabilities of ions in oxides and fluorides. J. Appl. Phys. 73, 348 (1993).CrossRefGoogle Scholar
28Kato, J., Kagata, H. and Nishimoto, K.: Dielectric properties of (PbCa) (MeNb)O3 at microwave frequencies. Jpn. J. Appl. Phys. 31, 3144 (1992).CrossRefGoogle Scholar
29Penn, S.J., Alford, N.McN., Templeton, A., Wang, X., Xu, M., Reece, M. and Schrapel, K.: Effect of porosity and grain size on the microwave dielectric properties of sintered alumina. J. Am. Ceram. Soc. 80, 1885 (1997).CrossRefGoogle Scholar