Enhanced electrical properties in KNN-based ternary ceramics with high Curie temperature

(1 − x)K_0.48Na_0.52Nb_0.965Sb_0.035O₃–x(0.9Bi_0.5Na_0.5ZrO₃–0.1BaSnO₃) [abbreviated as KNNS-x(BNZ-BS)] lead-free piezoelectric ceramics were designed and fabricated by using the conventional solid-state method. The phase structure, microstructure, and electrical properties have been discussed in detail. The good comprehensive properties (d₃₃ ~ 390 pC/N; T_C ~ 302 °C, S_pos ~ 0.121%, S_uni ~ 0.133%, d₃₃* ~ 404 pm/V) can be obtained for the ceramic of x = 0.040 with R-T ferroelectric phase co-existence near room temperature. Moreover, a good temperature stability of S_uni (S_125 °C /S_RT ~ 84.09%) in the ceramics with x = 0.040 is obtained at the temperature range of room temperature to 125 °C. The enhancement of electrical properties as well as higher Curie temperature (d₃₃ ~ 390 pC/N; T_C ~ 302 °C) indicates that KNNS-0.040(BNZ-BS) ceramic is a promising lead-free piezoceramic, especially in high temperature applied field.