The preparation and the effects of K/Na ratio on the electrical properties of 0.95(Na_0.96-xK_xLi_0.04)(Nb_0.89Sb_0.07Ta_0.04)O₃ - 0.05KNbO₃ lead-free ceramics

0.95(Na_0.96-xK_xLi_0.04)(Nb_0.89Sb_0.07Ta_0.04)O₃ - 0.05KNbO₃ (abbreviated as K_xNLNST-KN, x = 0.32 - 0.52) lead-free piezoelectric ceramics were prepared by using the conventional solid-state sintering method, and the intentional addition of a pre-calcined KNbO₃ powder was used as a sintering aid that might inhibit and compensate for the volatilization of alkali metals during the sintering process. The preparation of the ceramics and the effects of K/Na ratio on the structure and the electrical properties of these ceramics were studied in detail. Compared with the relatively higher sintering temperature of Li-, Sb-, and Ta-modified KNN ceramics reported in the literature, the dense ceramic samples were obtained at a reduced temperature of 1060 .deg. C, and the ceramics with x = 0.44 possessed optimal properties: d₃₃ = 298 pC/N, k_p = 48%, P_r = 21.9 μC/cm², and E_c = 11.5 kV/cm.