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Epitaxial Growth of BaZn1/3Ta2/3O3 Thin-Films for Microwave Applications

Published online by Cambridge University Press:  10 February 2011

G. Rong ,
L. Tsakalakos ,
J. Browning  and
N. Newman
G. Rong
Affiliation:
ECE Dept., Northwestern University, Evanston, IL 60208
L. Tsakalakos
Affiliation:
Material Science Dept., University of California, Berkeley, CA 94720
J. Browning
Affiliation:
ECE Dept., Northwestern University, Evanston, IL 60208
N. Newman
Affiliation:
ECE Dept., Northwestern University, Evanston, IL 60208
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Abstract

BaZn1/3Ta2/3O3 (BZT) ceramics are widely used in current microwave communication applications due to the material's large-dielectric constant (εr > 25), ultra-low loss tangent (tan δ < 2×10−5 at 2 GHz) and a near-zero temperature-coefficient of resonant frequency (τf∼0). In this paper, we report the first growth of epitaxial BZT thin films. The films are grown on MgO substrates using pulsed laser deposition. X-ray diffraction data indicate the films have a disordered pseudocubic perovskite structure with a small tetragonal distortion (i.e. a = b = 4.100 Å; c = 4.088 Å). An optimized substrate temperature of 575°C results in films which are over 98% oriented in the (001) direction and are relatively smooth (rms roughness of 5.2 Å). X-ray diffraction Φ scans of off-axis (202) reflection show four-fold symmetry, indicating a high degree of in-plane epitaxy, albeit with small angle grain boundaries. The refractive index of epitaxial BZT films is inferred to be 5 from Fabry- Perot fringes in optical transmission spectra. Substrate temperatures during growth are limited to ∼600°C as a result of Zn loss.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 574: Symposia BB – Multicomponent Oxide Films for Electronics , 1999 , 163
Copyright
Copyright © Materials Research Society 1999

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References

REFERENCES

1. “Materials and processes for Wireless Communication”, ed. T., Negas and H., Ling, Ceramic Transaction Vol. 53, American Ceramic Society Publications, Westerville, Ohio, 1995.Google Scholar
2. Negas, T., Yeager, G., Bell, S. and Amren, R., “Chemistry and Properties of Temperature Compensated Microwave Dielectrics”, National Institute of Standards and Technology Special Publications 804, Chemistry of Electronic Ceramic Materials, Proceedings of the International Conference, 7/17/90–7/22/90, Jackson, WY, p.21, 1991.Google Scholar
3. Desu, S. B. and O'Bryan, H. M., “Microwave Loss Quality of BaZnl/3 Ta2/3O3 Ceramics”, J Am. Ceram. Soc., 68 [10], 546 (1985).10.1111/j.1151-2916.1985.tb11521.xGoogle Scholar
4. Kawashima, S., Nishida, M., Ueda, I. and Ouchi, H., “Ba(Znl/3Ta2/3)O3 Ceramics with Low Dielectric Loss at Microwave Frequencies”, J. Am. Ceram. Soc. 66 421 (1983).10.1111/j.1151-2916.1983.tb10074.xGoogle Scholar
5. Tamura, H., Konoike, T., Sakabe, Y. and Wakino, K., “Improved High Q Dielectric Resonator with Complex Perovskite Structure”, J Am. Ceram. Soc. 67 C, 59– (1983).10.1111/j.1151-2916.1984.tb18828.xGoogle Scholar
6. Davies, P. K., “Influence of Structural Defects on the Dielectric Properties of Ceramic Microwave Resonators, Materials and Processes for Wireless Communication, ed. T., Negas and H., Ling, Ceramic Transitions Vol. 53, American Ceramic Society Publications, Westerville, Ohio, p. 137, 1995.Google Scholar
7. Rong, G., Newman, N., Shaw, B. and Cronin, D., “The Role of Ni and Zr Doping on Electrical, Optical, Magnetic and Structural Properties of Barium Zinc Tantalate Ceramics”, J. of Mat. Res., in press.Google Scholar