Lead-free piezoelectric (Na1/2K1/2)NbO3 ceramics doped with a BaTiO3 solution were prepared using a physicochemical method. The results indicate that the addition of the BaTiO3 solution significantly influences the sintering, microstructure, phase transition and electrical properties of NKN ceramics. The physicochemical method can not only artificially control the grain size but also can regulate the electrical properties. The effects of doping with a BT solution on the bulk density, dielectric, piezoelectric and ferroelectric properties were investigated. The enhanced ferroelectric and piezoelectric properties with a piezoelectric constant d33 of 182 pC/N, a planar electromechanical coefficient kp of 47%, a remanent polarization Pr of 22 μC/cm2 and a Curie temperature of 415 oC appear in the NKN-0.5BT ceramics of 0.005 mol% of a BT solutions. These results showed that NKN-BT ceramics fabricated by a physicochemical method are promising lead free piezoelectric materials.

Keywords: NKN-BT, Piezoelectric properties, Physicochemical method, Lead-free.