Electric field-induced giant strain and piezoelectricity enhancement effect in (Bi1/2Na1/2)0.935+xBa0.065Ti1−x(Pr1/2Nb1/2)xO3 lead-free ceramics

Lead-free (Bi1/2Na1/2)0.935+xBa0.065Ti1−x(Pr1/2Nb1/2)xO3 (BNBT–x PN) piezoelectric ceramics were prepared by the conventional solid-state reaction method and the crystal structure and electrical properties were systematically investigated. X-ray diffraction patterns revealed that the (Pr1/2Nb1/2)4+ completely diffused in the BNBT lattice in the studied composition range. An appropriate amount of (Pr1/2Nb1/2)4+ additive enhanced the dielectric, ferroelectric, and piezoelectric properties of BNBT ceramics. The Pr and d33 increased from 29.1 μC/cm2 and 121 pC/N of pure BNT to 32.8 μC /cm2 and 221 pC/N of modified ceramics with x=0.0050, respectively. Furthermore, electric field-induced strain was enhanced to its maximum value (Smax=0.34%) with normalized strain (d33*=Smax/Emax=567 pm/V) at an applied electric field of 60 kV/cm for x=0.0075. These findings have great potential for actuator and multifunctional device applications, which may also open up a range of new applications.