Dielectric Studies of Ba Substitution in Lead Zinc Niobate-Lead Zirconium Titanate Ceramics by Precipitation Method

Abstract

The polycrystalline samples of (Pb0.90Ba0.10) [(Zn1/3Nb2/3)0.20-(Zr0.51Ti0.49)0.80]O3 [PBZN-PZT] compositions ceramics have been synthesized by substitution of barium in PZN-PZT by precipitation method and finally by modified columbite method. Xray diffraction (XRD) analysis of (Pb0.90Ba0.10)(Zn1/3Nb2/3)O3 (PBZN) and PBZN-PZT shows a cubic and mixed phase of tetragonal and rhombohedral pure perovskite structure at room temperature. The dielectric dispersion of the solid solutions of PBZN-PZT has been studied as a function of temperature for the frequency range from 100 Hz to 1 MHz. The temperature (T) variation of the real components (ε ) at different frequencies of the dielectric permittivity shows a broad maximum. The diffuse peaks in permittivity versus temperature confirm the relaxor behaviour of PBZN-PZT. The frequency dependence of maximum temperature (Tm) in these compounds with barium substitution is modeled using Vogel-Fulcher relation.