High energy storage properties and dielectric behavior of (Bi0.5Na0.5)0.94Ba0.06Ti1−x(Al0.5Nb0.5)xO3 lead-free ferroelectric ceramics.

The influence of B-site (Al 0.5 Nb 0.5 ) 4+ complex-ion substitution on the phase transition, microstructure, dielectric, ferroelectric, and energy storage properties of (Bi 0.5 Na 0.5 ) 0.94 Ba 0.06 Ti 1− x (Al 0.5 Nb 0.5 ) x O 3 (BNBT -x AN) ceramics was systematically investigated. BNBT- x AN ceramics showed single-phase perovskite structure without an obvious phase transition after adding AN. Compact and uniform microstructure with almost the same grain morphology and size was obtained. The AN doping produced slimmer P – E loops and thus improved energy storage property. At the composition of x =0.04 and electric field of 70 kV/cm, the energy storage density achieved the optimum value of 0.70 J/cm 3 . The temperature dependence of dielectric constant ε r and dielectric loss tan δ illustrated a noticeable diffuse phase transition characteristics in BNBT -x AN ceramics. These results indicated that the BNBT-AN system may be a promising lead-free material for high energy storage density capacitor. [ABSTRACT FROM AUTHOR]