Variation of Dielectric Constant with the Volume Fraction of Pyrochlore Phae in the PMN-Polychlore Diphasic System ; Application of General Effective Media Equation

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J. Korean Ceram. Soc. > Volume 30(1); 1993 > Article

Journal of the Korean Ceramic Society 1993;30(1): 78.

Pyrochlore상의 부피분율에 따른 PMN-Pyrochlore 2상 혼합체의 유전율변화;General Effective Media식의 적용

허강일, 김정주, 김남경, 김진호, 조상희

경북대학교 무기재료공학과

Variation of Dielectric Constant with the Volume Fraction of Pyrochlore Phae in the PMN-Polychlore Diphasic System ; Application of General Effective Media Equation

ABSTRACT

In PMN-pyrochlore phase mixtures, dielectric constant was measured as a function of the volume fraction of pyrochlore phase and considered with general effective media(GEM) equation. For the application of GEM equation to this system, the critical volume fraction(Vc) where connectivity between the perovskite PMN and pyrochlore phase changed from 0-3 to 3-3, was determined based on the each particle size ratio of two phases with microstructural observation. And then the t value was determined from modified percolation powder-law dependence ( K-Kc (V-Vc)t). In the case of applying such values of t and Vc to the GEM equation, which provided a reasonable fit to the measured dielectric constant within the experimental error range.