(Li, Ta, Sb) modified (K, Na)NbO3 ceramics as high temperature dielectric materials

Abstract

A high temperature dielectric material of (Li, Ta, Sb) modified (K, Na)NbO3 (KNLNTS) ceramics with excellent temperature stability was prepared by a reactive templated grain growth (RTGG) method. The effects of sintering temperature on the phase structure, microstructure and electric properties of the ceramics were investigated. The XRD and SEM results revealed that the structure and microstructure of the ceramics could be controlled by changing the sintering temperature. Multiphase and cation disordering in the ceramics due to compositional inhomogeneity resulted in relaxor behavior, thus improving the temperature stability of the ceramics greatly. The KNLNTS ceramics sintered at 1150°C exhibit high permittivity maximum (~2000) and low dielectric loss (<4%) at a temperature range of 120–335°C, and the capacitance variation (ΔC/C185°C) maintains within ±15% at this temperature range, showing that KNLNTS ceramics is a promising candidate for high temperature MLCCs applications.