(K0.5Na0.5)NbO3–Bi(Zn0.5Zr0.5)O3 perovskite ceramics: High relative permittivity, low dielectric loss and good thermal stability

Abstract

A novel lead-free perovskite ceramic system with the composition of (1−x)(K0.5Na0.5)NbO3–xBi(Zn0.5Zr0.5)O3 [(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 Δε/ε115°C value (≤±15%) and relatively high permittivity (~1500) over the temperature range from 115 to 343°C. Moreover, the dielectric loss was dramatically reduced below 4.5% from room temperature to ~544°C, which suggests that this ceramic is a candidate for high-temperature capacitor application.