Temperature stability and phase transition of Li 0.02(K xNa 1− x) 0.98NbO 3 ceramics

Abstract

Li 0.02(K x Na 1− x ) 0.98NbO 3( x = 0.35–0.55) ceramics were prepared using the conventional solid state sintering method. The thermal behaviors of Li-modified (K x Na 1− x )NbO 3 ceramics were investigated from −30 to 150 °C, and the effect of Na/K ratio in (K x Na 1− x )NbO 3 ceramics on thermal behavior and electrical properties was also studied. In the case of Li 0.02(K x Na 1− x ) 0.98NbO 3 ceramics with 0.5 wt.% ZnO, the transition temperature was sharply decreased because of a phase transition as the composition range of x was 0.425–0.475. From the results of the temperature dependence of piezoelectric properties, it is assumed that the Na-rich phase is less stable than the K-rich phase for temperature change.