Perovskite structured BNT ceramics have been considered as a good candidate for lead-free piezoelectric material . Because BNT ceramics have as trong remanent polarization (Pr¼38 μC/cm2) and high coercive field (Ec¼73 kV/cm) at room temperature [7]. However, there are some drawbacks in poling BNT ceramics because of its high coercive field and relatively high conductivity. Also, BNT ceramics show a relatively high reverse piezoelectric coefficient (498pm/V) at high electric fields [8]. The high inverse piezoelectric effects can cause very large strain values [8].