Enhanced piezoelectric properties of 3-1 type porous 0.94Bi0.5Na0.5TiO3-0.06BaTiO3 ferroelectric ceramics

To develop lead-free compounds with high electromechanical properties is a critical issue for the piezoelectric materials development. Bi0.5Na0.5TiO3 (BNT) and its solid solutions are the famous lead-free family. There have been lots of efforts contributed to improve their piezoelectric properties by doping or texturing. Here, we developed 3-1 type porous 0.94Bi(0.5)Na(0.5)TiO(3)-0.06BaTiO(3) (BNT-6BT) ceramic by a freeze-casting technique. The porous ceramics showed enhanced piezoelectric coefficient (d(33)) and electrical-induced strain. The d(33) can reach 182 pC/N and the maximum strain is 0.42% at an electric field of 70 kV/cm, which is much higher than values on the dense BNT-6BT ceramic. These enhanced properties would be explained by the domain structures and the surface effect. With the previous studies, this result indicates that the 3-1 type porous structure has the potential to be widely applied to improve the piezoelectric properties of the lead-free ferroelectric ceramics.