Effect of Zirconium Substitution on the Electrical Properties of Ferroelectric (Bi0.5Na0.5)0.94Ba0.06TiO3 Ceramics

Abstract

Ceramic samples of Zirconium substituted Bismuth Sodium Barium Titanate of composition (Bi0.5Na0.5)0.94Ba0.06(Ti1-xZrx)O3 with x = 0.0,0.04,0.08,0.1 and 0.2 have been synthesized following solid-state method. X-ray diffraction studies indicated the formation of phase pure materials with rhombohedral structure for 0.0<x<0.1. A small extra peak near 2θ ~ 28' is noticed for composition x = 0.10. SEM studies indicated substitution of Zr led to an increase in grain size. Dielectric studies revealed a decrease in dielectric constant with Zr substitution up to x = 0.08. Sample with x = 0.10 showed paraelectric behavior indicating the critical concentration of Zr necessary for ferroelectric and paraelectric behavior in those samples lies between 0.08 and 0.10. Impedance measurements showed grain boundary effect and negative temperature coefficient of resistivity behavior. A.C and D.C activation energies have been computed using Arrhenius relation from subsequent temperature regions for two different frequencies of 1 KHz and 10 KHz.