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Advances in Condensed Matter Physics
Volume 2013, Article ID 858406, 9 pages
http://dx.doi.org/10.1155/2013/858406
Research Article

Dielectric Properties of Φ(BZT-BCT)-(1−Φ) Epoxy Composites with 0-3 Connectivity

Department of Physics, National Institute of Technology, Rourkela 769008, India

Received 30 May 2013; Revised 11 September 2013; Accepted 28 September 2013

Academic Editor: Mohindar S. Seehra

Copyright © 2013 P. Mishra and P. Kumar. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Lead free ferroelectric ceramic [0.5[Ba(Zr0.2Ti0.8)O3]-0.5[(Ba0.7Ca0.3)TiO3]]/(BZT-BCT)-epoxy composites with 0-3 connectivity (particles connected in 3 dimensions) were prepared using hand lay-up technique followed by cold pressing for different volume fractions of (BZT-BCT) ceramic powder in the epoxy polymer matrix. The structural, microstructural, and dielectric properties of the composites have been investigated and discussed. XRD studies revealed the presence of both ceramic and polymer phases in the (BZT-BCT)-epoxy composites. SEM studies showed a uniform distribution of ceramic particles in the epoxy matrix, which confirmed the 0-3 connectivity in the composites. Dielectric studies revealed an increase in relative permittivity ( ) and decrease in dielectric loss ( ) in the composites with the increase in the volume fractions of the ceramics up to 20%. This can be ascribed to the increase in density of the composites and dielectric properties of the epoxy polymer. At room temperature (RT) and at 1 kHz frequency, 0.2(BZT-BCT)-0.8(epoxy) composite showed the highest relative permittivity . For the prediction of the effective dielectric constant of the composites, the experimental data were fitted to several theoretical equations. Effective medium theory (EMT) model and Yamada models were found to be useful for the prediction of the effective dielectric constant of studied composites.