Frequency and temperature dependence dielectric study of strontium modified Barium Zirconium Titanate ceramics obtained by mechanochemical synthesis

Abstract

A detailed investigation of the crystal structure and electrical properties of Ba1-xSrxZr0.05Ti0.95O3 (x = 0.1, 0.2, 0.3 and 0.5) ceramics prepared using high energy ball milling is presented in this manuscript. The X-ray diffraction patterns confirmed the single phase formation of the examined compounds. The substitution of Sr2+ drove the crystal symmetry of the system from tetragonal to cubic at x = 0.3. The structural conformation was also carried out employing the Rietveld refinement analysis. The microstrutural study was developed through the scanning electron microscopy, which showed a decrement in the grain size with Sr doping. Using the impedance spectroscopic technique, the electrical microstructure of the system was presented and the overall electrical properties indicated the presence of grains separated by grain boundaries and is explained in terms of the bricklayer model. Negative temperature coefficient of resistance behavior was observed in all compositions. The activation energy estimated from impedance, modulus and conductivity formalism confirmed that the oxygen vacancies play an important role in the conduction mechanism.