Abstract: Lead-free piezoelectric(Na _0.52 K _0.48-x Li _x)(Nb _0.86 Ta _0.10 Sb _0.04)O₃ ceramics were prepared by solid state reaction. The microstructure, phase and electric properties were studied for (Na _0.52 K _0.48-x Li _x )(Nb _0.86 Ta _0.10 Sb _0.04 )O₃ samples with different Li content (x being 0, 0.02, 0.04, 0.06, 0.08). Results show that their phases, piezoelectric, dielectric and ferroelectric properties of (Na _0.52 K _0.48-x Li _x)(Nb _0.86 Ta _0.10 -Sb _0.04) O₃ lead-free ceramics are μch influenced by the content of Li ions. The piezoelectric properties are enhanced when Li content increases from 0 to 0.04, and decreased when Li content (x) is more than 0.04. Best electric properties are obtained for the sample when x equals 0.04,with its piezoelectric constant d33 being 260pC/N, dielectric loss tanδ being 0.027, planar coupling factor k p being 50%, remanent polarization P r being 22μC·cm^-2, coercive electric field E c being 0.95kV·mm^-1, Curie temperature being 316℃. With the increase of Li content, the coercive electric field E c increases obviously, and the Curie temperature is also enhanced.

Key words: sodium potassium tantalum niobate, lead-free piezoelectric ceramics, piezoelectric properties, ferroelectric properties, dielectric properties