Effects of the co-addition of LiSbO 3–LiTaO 3 on the densification of (Na 1/2K 1/2)NbO 3 lead free ceramics by atmosphere sintering

Abstract

Pure phase perovskite 0.94(Na 1/2K 1/2)NbO 3–0.03LiSbO 3–0.03LiTaO 3 (0.94NKN–0.03LS–0.03LT) lead-free piezoelectric ceramics were prepared by the conventional solid-state reaction method. Due to the co-addition of LiSbO 3–LiTaO 3, the 0.94NKN–0.03LS–0.03LT ceramics prepared by atmosphere sintering at 1040 °C exhibit high relative density, being 94.73%, and rather homogenous microstructure. X-ray diffraction (XRD) measurement confirmed that the sintered ceramics exhibit pure tetragonal perovskite structure. The 0.94NKN–0.03LS–0.03LT ceramics exhibit excellent integral electrical properties, in which the value of piezoelectric constant d 33 is 228 pC/N, the electromechanical coupling factors K p and K t are 0.220 and 0.230, respectively, the mechanical quality factor Q m is 32.19, and the remnant polarization P r is 23.06 μC/cm 2. Such excellent electrical properties are considered as correlating with the high relative density of the synthesized ceramics induced by the co-doping of LiSbO 3–LiTaO 3.