Studies Of Structural, Dielectric And Electrical Properties Of A/B Site Modified (Na0.5bi0.5)Tio3 Ceramic Oxides

Abstract

In recent years, there is an urgent need for the development of lead-free alternative ferroelectrics to replace the most dominant lead-based ferroelectrics (e.g., Lead zirconate titanate (PZT)) due to the toxicity of lead. Sodium bismuth titanate (Na0.5Bi0.5)TiO3 (NBT) based erroelectrics are supposed to be the future materials for solid state electronics devices because of their relatively high Curie temperatures and high remnant polarization among the non-lead ferroelectrics. The present work deals with the synthesis and analysis of the electrical properties of NBT based lead free ferroelectric materials with suitable substitution at A and B sites.In this context, the systematic studies of lanthanum (La) / yttrium (Y) and zirconium (Zr) substitution at A and B sites of NBT have been undertaken through structural, dielectric and impedance spectroscopy studies. NBT and modified NBT samples were synthesized by conventional solid state reaction route. The desired phase and crystal structure formation of the synthesized materials were confirmed by X-ray diffraction (XRD) analysis. The preliminary XRD analysis of the material revealed rhombohedral crystal system with hexagonal axis. The scanning electron micrographs (SEM) were taken at different magnifications to visualize the microstructure (grain size, grain distribution, voids etc.) of the materials. The appearance of the characteristic peak of BO6 octahedra in FTIR spectrum confirms the formation of perovskite phase.