The enhanced piezoelectric performance of Bi1/2Na1/2TiO3–BaTiO3 ceramics by Ba0.77Ca0.23TiO3 substitution

Abstract In this study, lead-free (1− x )Bi 0.47 Na 0.47 Ba 0.06 TiO 3 – x Ba 0.77 Ca 0.23 TiO 3 (BNBT– x BCT, x =  0–0.12) ceramics were fabricated by ordinary ceramic sintering technique. The results show that Ba 0.77 Ca 0.23 TiO 3 (BCT) has diffused into Bi 0.47 Na 0.47 Ba 0.06 TiO 3 (BNBT) lattices to form a new solid solution BNBT– x BCT. Moderate substitution of BCT in BNBT– x BCT ( x ⩽  0.01) ceramics can enhance the piezoelectric and ferroelectric properties; meanwhile, depolarization temperature of the ceramics does not decrease. BNBT–0.01BCT ceramic exhibits the best piezoelectric properties and strongest ferroelectricity: piezoelectric coefficient d 33  = 178 pC/N; electromechanical coupling factors k t  = 50% and k p  = 27%; quality factor Q m  = 131; remnant polarization P r  = 36 μC/cm 2 ; coercive field E c  = 24.5 kV/cm. The piezoelectric properties, ferroelectric characteristics and depolarization mechanism of the ceramics are investigated and discussed.