Journal of Material Sciences & Engineering

Low- Frequency Dielectric Dispersion and Impedance Spectroscopy of Lead-Free Na0.5 Bi0.5 Tio3 (NBT) based Ferroelectric Ceramic

Abstract

B.Tilak

(Na0.5Bi0.5)0.89Ba0.11 Zr0.04Ti0.96O3 (0.11BNBZT) ceramic were prepared by using solid-state reaction method. A single phase perovskite (ABO3) structure with tetragonal symmetry was confirmed by X-ray diffraction. The dielectric behavior, impedance relaxation were investigated in a wide range of temperature (30°C-600°C) and frequencies (45Hz-5MHz). The grain morphologies were analyzed by using a Scanning Electron Microscopy (SEM) analysis. The temperature dependence of dielectric behavior and the frequency dependence of impedance relaxation were investigated. A broaden dielectric constant peak were observed over a wide temperature range and also indicate a relaxor behavior. The complex impedance plot exhibited semicircle plot, which is explained by the grain effect of the bulk. The center of the impedance semicircles lie below the real axis, which indicates that the impedance response is a Cole-Cole type relaxation.