Phase Structure and Electrical Properties of (K _0.48 Na _0.52 )(Nb _0.95 Ta _0.05 )O ₃ ‐LiSbO ₃ Lead‐Free Piezoelectric Ceramics

Abstract

(1− x )(K 0.48 Na 0.52 )(Nb 0.95 Ta 0.05 )O 3 – x LiSbO 3 [(1− x )KNNT− x LS] lead‐free piezoelectric ceramics were prepared by the conventional solid‐state sintering method. A morphotropic phase boundary (MPB) between orthorhombic and tetragonal phases was identified in the composition range of 0.03< x <0.05. The ceramics near the MPB exhibit a strong compositional dependence and enhanced electrical properties. The (1− x )KNNT– x LS ( x =0.04) ceramics exhibit good electrical properties ( d 33 =250 pC/N, k p =45.1%, k t =46.3%, T c =348°C, T o − t =74°C, P r =25.9 μC/cm 2 , E c =10.7 kV/cm, ɛ r ∼1352, tan δ∼3%). These results show that (1− x )KNNT– x LS ceramic is a promising lead‐free piezoelectric material.