Phase Transitional Behavior and Dielectric Properties of (Ba,Ca)(Ti,Zr)O3–Bi(Zn,Zr)O3 Lead-Free Ceramics

Abstract

The (1-x)(Ba0.98Ca0.02)(Ti0.95Zr0.05)O3–xBi(Zn0.5Zr0.5)O3 [BCZT–xBZZ, x = 0.005–0.06] lead-free solid solution ceramics were synthesized by a conventional solid state reaction method. The effect of Bi(Zn0.5Zr0.5)O3 addition on the crystal structure, microstructure, relaxor behavior and dielectric properties of the (Ba0.98Ca0.02)(Ti0.95Zr0.05)O3 ceramics has been studied. X-ray diffraction shows that all the ceramics possess a single phase of perovskite structure. The BCZT–xBZZ ceramics change from tetragonal phase to pseudocubic phase with the content of BZZ increasing. Moreover, the grain size is affected by BZZ addition. The BCZT–xBZZ ceramics become considerably dense with the proper amount of BZZ introduction. The relative permittivity ϵr and loss tangent tanδ vary with the increasing BZZ content. Temperature dependence of the dielectric properties indicates that as the concentration of BZZ increases, the BCZT–BZZ solid solution ceramics exhibit more relaxor-like behavior. Furthermore, the BCZT–xBZZ ceramics exhibit low dielectric loss and excellent dielectric temperature stability in a wide temperature range, which indicates a potential application in devices under comparably high-temperature environment.