Synthesis and composition characterization of K0.5Na0.5NbO3–KSr2Nb5O15 ceramics

Abstract

KSr2Nb5O15 modified potassium sodium niobate ceramics ((1 – x)KNN–xKSN) were fabricated by a pressure-less solid-state method, using Bi as a sintering aid. Synthesis and composition characterization of the (1 – x)KNN–xKSN ceramics were investigated. It was found that the KSN addition was favorable to the densification of the (1 – x)KNN–xKSN ceramics due to the improvement of sintering temperature and the absence of abnormal grain growth. Induced by KSN, the KNN phase structure spontaneously transformed from perovskite to tetragonal tungsten bronze. The result suggested that for preparing KNN-based ceramics with high performance it is necessary to control the phase transformation. This study also opens up a new avenue for the investigation of the relationship between structure and performance in KNN ceramics.