Piezoelectric properties in perovskite 0.948(K0.5Na0.5)NbO3–0.052LiSbO3 lead-free ceramics

TLDR: In this article, a lead-free piezoelectric ceramics, with the nominal composition of 0.948(K 0.5Na0.5)NbO3-0.052LiSbO 3 (KNN-LS5.2), were synthesized by conventional solid-state sintering, and the pieziolectric and electromechanical properties were characterized as a function of temperature, which mimicked the compositional variation seen in the proximity of a morphotropic phase boundary.

Abstract: Lead-free piezoelectric ceramics, with the nominal composition of 0.948(K0.5Na0.5)NbO3–0.052LiSbO3 (KNN-LS5.2), were synthesized by conventional solid-state sintering, and the piezoelectric and electromechanical properties were characterized as a function of temperature. The Curie temperature of the KNN based perovskite material was found to be 368°C with an orthorhombic-tetragonal polymorphic phase transition (TO-T) temperature at approximately ∼35°C. The room temperature dielectric permittivity (e33T∕e0) and loss were found to be 1380 and 2%, respectively, with piezoelectric properties of k33∼62% and d33∼265pC∕N and k31∼30% and d31∼−116pC∕N. The temperature dependence of the properties mimicked the compositional variation seen in the proximity of a morphotropic phase boundary [e.g., lead zirconate titanate (PZT)], with a maxima in the dielectric and piezoelectric properties and a corresponding “softening” of the elastic properties. Unlike that found for PZT-type materials, the modified KNN material exhi...