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

In this study, lead-free (1-x)Bi0.47Na0.47Ba0.06TiO3-xBa(0.77)Ca(0.23)TiO(3) (BNBT-xBCT, x = 0-0.12) ceramics were fabricated by ordinary ceramic sintering technique. The results show that Ba0.77Ca0.23TiO3 (BCT) has diffused into Bi0.47Na0.47Ba0.06TiO3 (BNBT) lattices to form a new solid solution BNBT-xBCT. Moderate substitution of BCT in BNBT-xBCT (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 mu C/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. Published by Elsevier B.V.