Dielectric, Ferroelectric and Piezoelectric Properties of the Lead Free 0.9BaTiO3-(0.1-x)Bi0.5Na0.5TiO3-xBi(Mg0.5Ti0.5)O3 Solid Solution

Solid solution of 0.9BaTiO(3)-(0.1-x)Bi0.5Na0.5TiO3-xBi(Mg0.5Ti0.5)O-3 (BT-BNT-xBMT) system, where x = 0.00, 0.02, 0.04, 0.06, 0.08, 0.10, was synthesized by the solid state reaction. Dense BT-BNT-xBMT ceramics were obtained by sintering at 1,150-1,250C for 4h. The effect of BMT on crystal structure and electrical property of BT-BNT ceramics was investigated as a function of composition, x, using X-ray diffraction, dielectric spectroscopy, hysteresis and strain measurements. The crystal structure of solid solution BT-BNT-xBMT, where x = 0.00-0.10, successively transforms from tetragonal to pseudocubic symmetry, with increased BMT concentration. Temperature dependence of dielectric constant (E-r) and dielectric loss (tan) for BT-BNT-xBMT at various frequencies showed that phase transition of ceramics changed from ferroelectric to relaxor-like behavior as BMT content increased. Furthermore, remanent polarization (P-r), coercive field (E-c) and the normalized strain (d(33)*) of BT-BNT-xBMT ceramics tend to decrease with increasing BMT concentration.