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Journal of Materials
Volume 2013, Article ID 857201, 8 pages
http://dx.doi.org/10.1155/2013/857201
Research Article

Low Temperature Dielectric Relaxation in System

1Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, Noida 201307, India
2Department of Applied Science, Devender Singh Institute of Technology and Management, Ghaziabad 201001, India
3Department of Ceramic Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi 221 005, India

Received 6 December 2012; Accepted 31 December 2012

Academic Editor: Iwan Kityk

Copyright © 2013 Arvind Kumar et al. 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

We report on dielectric properties of polycrystalline (BBTF) ceramic system (, 0.06, 0.08, 0.10, 0.12, and 0.16). The materials were synthesized by solid state ceramic route. Solid solution formation has been confirmed by powder X-ray diffraction for compositions with . Crystal structure is tetragonal for and cubic for . Microstructures show that the average grain size is less than one micrometer (1 μ). Dielectric behavior has been studied as a function of temperature (100 K–400 K) and frequency. Composition with exhibits diffuse phase transition. Compositions with show ferroelectric relaxor behavior. This shows that diffuse ferroelectric transition behavior changes to relaxor type ferroelectric transition with increasing . Plots of dielectric loss (D) versus temperature shows broad maxima which shift to high temperature with increasing frequency, dispersion in dielectric loss decreases with below peak maxima and increases above. It may be attributed to Maxwell Wagner type relaxation process for low (~0.02) and relaxation of nanopolar regions for .