Li-modified Sodium Potassium Tantalum Niobate Lead-free Piezoelectric Ceramics

Lead-free piezoelectric (Na0.52K0.48-xLix)(Nb0.86Ta0.10Sb0.04)O3 ceramics were prepared by solid state reaction. The microstructure, phase and electric properties were studied for (Na0.52K0.48-xLix) (Nb0.86Ta0.10Sb0.04)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 (Na0.52K0.48-xLix)(Nb0.86Ta0.10-Sb0.04)O3 lead-free ceramics are much 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 (a;) 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 tanδbeing 0.027, planar coupling factor kp being 50%, rema-nent polarization Pr being 22μC.cm-2, coercive electric field Ec being 0.95kV.mm-1, Curie temperature being 316℃. With the increase of Li content, the coercive electric field Ec increases obviously, and the Curie temperature is also enhanced.