IMPEDANCE AND MODULUS SPECTROSCOPY CHARACTERIZATION OF SODIUM-BISMUTH TITANATE-BASED LEAD-FREE FERROELECTRIC MATERIALS

In this paper, we present impedance spectroscopy of Sodium Bismuth Titanate-based materials belonging to (1-x)Na1/2Bi1/2TiO3 - xBaTiO(3) (x = 0.04) (NBT - BT) system. NBT-BT ceramics are prepared by high temperature solid-state reaction method. X-ray di r raction technique showed single-phase polycrystalline sample with an ABO(3) perovskite structure. Dielectric behavior and the impedance relaxation were investigated in a wide range of temperature (room temperature (RT) - 500 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 one impedance semicircle identified over the frequency range of 1 kHz-1MHz, which is explained by the grain e r ect of the bulk. The centers of the impedance semicircles lie below the real axis, which indicates that the impedance response is a Cole-Cole type relaxation.