Abstract
Perovskite type Ba-0.8 La-0.133 Ti-0.90 Sn-0.1 O-3 ceramic has been prepared through a solid-state reaction route. The effects of cationic substitution of La3+ and Sn4+ for titanium in the A and B sites for BaTiO3 perovskite lattice on symmetry and dielectric properties were investigated. The samples are of single phase with rhombohedral structure of R (3) over bar C space group. Impedance spectrum results indicate that the electrical properties are strongly dependent on temperature and have a good correlation with the sample microstructure in different temperature. Nyquist plots (Z '' versus Z') show that the conductivity behavior is accurately represented by an equivalent circuit model which consists of a parallel combination of a bulk resistance and constant phase elements (CPE). The near value of activation energies obtained from the analyses of modulus and conductivity data confirms that the transport is through ion hopping mechanism in the investigated materials. (c) 2012 Elsevier Ltd. All rights reserved.