(K0.5Na0.5)NbO3-Bi(Zn0.5Zr0.5)O-3 perovskite ceramics: High relative permittivity, low dielectric loss and good thermal stability

摘要

A novel lead-free perovskite ceramic system with the composition of (1 - x)(K0.5Na0.5)NbO3-xBi(Zn0.5Zr0.5)O-3 [(1-x)KNN-xBZZ, x=0-0.02] was developed. The effects of BZZ addition on the phase transition, microstructure and dielectric performances of KNN ceramic were systematically investigated. The BZZ addition can significantly enhance the relative permittivity and thermal stability of permittivity of ceramics below the Curie temperature. When x=0.015, the ceramic possessed the optimized dielectric performance with small Delta epsilon/epsilon(115 degrees C) value (<= +/-15%) and relatively high permittivity (similar to 1500) over the temperature range from 115 to 343 degrees C. Moreover, the dielectric loss was dramatically reduced below 4.5% from room temperature to similar to 544 degrees C, which suggests that this ceramic is a candidate for high-temperature capacitor application. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All tights reserved.