Impedance and modulus spectroscopy characterization of lead free barium titanate ferroelectric ceramics

In this work, dense BaTiO3 ceramics were successfully prepared by the solid state reaction process. X-ray diffraction technique showed single-phase polycrystalline sample with perovskite structure. Dielectric behavior and the impedance relaxation were investigated in a wide range of temperature (room temperature (RT) - 40 degrees C) and frequency (1 kHz-1 MHz). A broad dielectric constant peak was observed over a wide temperature range around the phase transition temperature. The complex impedance plot exhibited two impedance semicircles identified over the frequency range of 1 kHz-1 MHz, which is explained by the grain and grain boundary effects. The presence of non-Debye type of relaxation has been confirmed by the complex impedance analysis. The centers of the impedance semicircles lie below the real axis, which indicates that the impedance response is a Cole Cole type relaxation. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.