Properties of (Na 0.53K 0.4Li 0.07)Nb 1− x% Sb x% O 3 ceramics with high lithium and antimony content

Abstract

(Na 0.53K 0.4Li 0.07)Nb 1− x% Sb x% O 3 (NKLNS x) piezoelectric ceramics with high content of lithium and antimony have been prepared by the solid-state reaction technique. The effect of Sb content on the crystallographic structure, phase transitions, piezoelectric and ferroelectric properties of NKLNS x ceramics is studied. The X-ray diffraction results suggest that the structure of the ceramics changes from pure tetragonal phase to the coexistence of orthorhombic and tetragonal phases with the increasing x, and that a little amount of second phase, LiSbO 3, is formed. The increase of Sb content induces a decrease of the Curie temperature T C and an increase of the orthorhombic–tetragonal phase transition temperature T O-T. The two compositions, NKLNS8.8 and NKLNS9.1, with T O-T closest to room temperature, possess optimum properties, with d 33 ∼ 290 pC/N, ɛ r ∼ 1340, and P r ∼ 24.2 μC/cm 2. These properties are superior to those of previously reported (K, Na, Li)(Nb, Sb)O 3 systems with low content of lithium and antimony. The thermal stability investigations show that the change of k p is minor for the ceramics that do not undergo a phase transition in the examined temperature range.