Dielectric Property and Phase Transition of (K0.5Na0.5)1−x Li x Nb1−y Sb y O3 Piezoelectric Ceramics

Abstract

(K0.5Na0.5)1−xLixNb1−ySbyO3 (KNLNSx–y, x = 0–10 mol % and y = 2–8 mol %) lead-free piezoelectric ceramics were prepared by conventional mixed oxide method. The effects of Li and Sb substitutions on the dielectric properties and phase transitions of the KNLNSx–y ceramics were studied. The results indicate that the relative permittivity ϵ r and loss tangent tanδ vary with the amount of Li and Sb. For the KNLNSx–5 ceramics, the orthorhombic−tetragonal phase transition temperature (TO−T) decreases and the Curie temperature (TC) increases with the increasing amount of Li. The TO−T and TC of the KNLNS2–y ceramics decrease with increasing amount of Sb. Moreover, the diffusiveness in the ceramics concerned seems to occur mainly due to the cations disorder of Nb5 + and Sb5 + at B-site.