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°C) and frequency (1kHz–1MHz). 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 1kHz–1MHz, 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.