Piezoelectric properties of [(K1−xNax)0.95Li0.05]0.985Ca0.015(Nb0.95Sb0.05)0.985Ti0.015O3 lead-free ceramics

In this paper, we have investigated the effect of K/Na ratio on the electrical properties of [(K1−xNax)0.95Li0.05]0.985Ca0.015(Nb0.95Sb0.05)0.985Ti0.015O3 (K1−xNaxLCNST) lead-free piezoelectric ceramics prepared by the conventional solid-state method. A pure phase is observed in these ceramics with x = 0.30–0.80, and the K/Na ratio results in the phase transition of K1−xNaxLCNST ceramics. The Curie temperature of K1−xNaxLCNST ceramics decreases with the increase of Na content. A higher dielectric constant is observed in the ceramic with x = 0.40, and the dielectric loss almost decreases with the increase of Na content. Moreover, an enhanced piezoelectric behavior (d33 ~ 227 pC/N and kp ~ 45.3 %) has been demonstrated in the K1−xNaxLCNST ceramic with x = 0.40. Therefore, optimizing the K/Na ratio is an effective way to enhance the piezoelectric properties of K1−xNaxLCNST ceramics.