In this study, piezoelectric and dielectric properties of the (Na0.5K0.5)NbO3-(1-x)(Bi0.5Na0.5)TiO3- xBaTiO3 [NKN-(1-x)BNT-xBT] ceramics were investigated. The lead-free NKN-(1-x)BNT-xBT ceramics were fabricated by a conventional mixed oxide method. The results indicate that the addition of BaTiO3 significantly influences the sintering, microstructure, phase transition and electrical properties of NKN-BNT ceramics. A gradual change in the piezoelectric and dielectric properties was observed with the increase of BT contents. The dielectric constant, piezoelectric constant (d33) and electromechanical coupling factor (kp) increased at the morphotropic phase boundary (MPB). The d33=184 pC/N, kp=0.38, dielectric constant=1455 with dielectric loss value of less than 1% were obtained for the NKN-0.95BNT-0.05BT ceramics sintered at 1150℃ for 2h. These results demonstrate that the NKN-(1-x)BNT-xBT ceramics is an attractive candidate for lead-free piezoelectric materials.
