LAUSR

The research on Na0.5Bi0.5TiO3 based lead-free piezoelectric ceramics attracted widely attention during last decades. However, the electrical performance is still much inferior to that of lead-based counterparts, which limits its practical applications. Based on this situation, a ternary system of Na0.5Bi0.5TiO3–K0.5Bi0.5TiO3–BaTiO3 [(1 − 2x)NBT–xKBT–xBT] is constructed in this work, hoping to further improve its piezoelectric response. The ceramics were fabricated by the traditional solid state reaction approach, and their structure and electrical performance were studied systematically. Excellent piezoelectric properties with d33 = 146 and kp = 26.5% were obtained at x = 0.08, which was supposed to be related with the coexistence of tetragonal and rhombohedral phases and appropriate grain size. Besides these, a relatively high dielectric constant (εr = 2250), a high remnant polarization (Pr = 31.5 µC/cm2) and low coercive field (Ec = 1.54 kV/mm) were also obtained at this composition. This work provides a new paradigm for the further optimization of NBT–KBT–BT based lead-free piezoelectric ceramics.