However, pure BNT ceramic
has high coercive field (Ec¼73 kV/cm), making the poling
of the ceramics extremely difficult. In addition, pure BNT
ceramic usually exhibits very poor piezoelectricity (d33¼58
pC/N). To decrease the coercive field and improve the
piezoelectric properties, a number of solid solutions of
BNT with ABO3-type ferroelectrics perovskite materials
such as BNT–Bi0.5K0.5TiO3 [