Evaluation of Microwave Dielectric Properties in <TEX>$(Pb_{0.5}Ca_{0.5})(Fe_{0.5}Ta_{0.5})O_3$</TEX> Ceramics by the Dielectric Mixing Rule

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J. Korean Ceram. Soc. > Volume 37(3); 2000 > Article

Journal of the Korean Ceramic Society 2000;37(3): 240.

유전체 혼합 법칙을 이용한 $(Pb_{0.5}Ca_{0.5})(Fe_{0.5}Ta_{0.5})O_3$세라믹스의 마이크로파 유전특성 평가

박흥수, 윤기현, 김응수¹

연세대학교 세라믹공학과
¹경기대학교 재료공학과

Evaluation of Microwave Dielectric Properties in $(Pb_{0.5}Ca_{0.5})(Fe_{0.5}Ta_{0.5})O_3$ Ceramics by the Dielectric Mixing Rule

ABSTRACT

The microwave dielectric properties of the complex perovskite (Pb0.5Ca0.5)(Fe0.5Ta0.5)O3 ceramics were investigated with the porosity and the dielectric mixing rule. Assuming that the specimens were mixtures of real dielectrics and pores, with 3-0 connectivity, the ionic polarizabilities modified by Maxwell's equation were more close to the theoretical values rather than those modified by Wiener's equation in porous specimens. The theoretical dielectirc loss were obtained with the infrared reflectivity spectra from 50 to 4000cm-1, which were calculated by Kramers-Kronig analysis and classical osciallator model. The relative tendency of dielectric loss calculated from the theoretical value and Maxwell's equation in the specimens with different porosities was in good agreement with the one by the post resonant method.

Key words: $(Pb_{0.5}Ca_{0.5})(Fe_{0.5}Ta_{0.5})O_3$, Ionic polarizability, Dielectric mixing rule, Infrared reflectivity spectra, Dispersion parameter