Phase Transition, Large Strain and Energy Storage in Ferroelectric (Bi0.5Na0.5)TiO3-BaTiO3 Ceramics Tailored by (Mg1/3Nb2/3)4+ Complex Ions.

Lead-free relaxor-ferroelectric (Mg_1/3Nb_2/3)⁴⁺ complex ions modified (Bi_0.5Na_0.5)_0.94Ba_0.06TiO₃ (BNBT-xMN) ceramics were fabricated by traditional solid-phase reaction sintering, and the effects of (Mg_1/3Nb_2/3)⁴⁺ complex ions on the structural, ferroelectric, dielectric, energy storage, and strain properties of these ceramics were studied. All of the samples illustrated a single perovskite phase with a pseudo-cubic structure. Electric field-induced polarization and strain hysteresis loops indicated the occurrence of reversible ferroelectric-to-relaxor phase transition, which gave rise to a large strain of 0.49%. (Mg_1/3Nb_2/3)⁴⁺ complex ions greatly influenced the coercive field and remanent polarization of the ceramics; these properties also affected energy storage density of the materials. The optimal energy storage density and efficiency of the ceramics were 0.54 J/cm³ and 38.4%, respectively, when x = 0.04. These results may stem from the electric field-induced transition between the ferroelectric and relaxor-ferroelectric phase of the proposed ceramics. [ABSTRACT FROM AUTHOR]