Enhanced Storage Energy Density with Excellent Temperature-Stable Dielectric Properties of (1-X)(Bi0.5na0.5)0.94ba0.06tio3-Xagnbo3 Lead-Free Ceramics

Abstract

Lead-free (1-x)(Bi0.5Na0.5)0.94Ba0.06TiO3-xAgNbO3 (abbreviated as BNTBT-100xAN) ceramics were fabricated using a conventional solid-phase reaction technology. The effect of the antiferroelectric AgNbO3 dopants for the fatigue resistance, energy-storage density, temperature-stable permittivity, and conductivity mechanism was systematically investigated. The addition of AgNbO3 led to the decrease of remnant polarization and  the increase of dielectric breakdown strength, a large effective energy-storage density of ~ 1.27 J/cm3 corresponding to the conversion efficiency of ~ 77.5 % for x = 0.05 ceramic were attained under applied 105 kV/cm field. Meanwhile, it exhibited an outstanding fatigue-resistant performance at 70 kV/cm fixed field up to 105 cycles accompanied with outstanding temperature-stable properties in the temperature range of 30 °C ~ 120 °C. Besides, BNTBT-5AN sample has also obtained outstanding temperature-stable permittivity, which was associated with the enhancement of the ergodic relaxor domain structure. A little variance of dielectric content (Δε'/ε'150°C £ ± 15 %) was acquired from 40 °C to 387 °C with a small tangent less (tand £ 0.05) between 50 °C and 461 °C. Hence, it revealed that the high energy storage properties and excellent dielectric temperature stability for BNTBT-5AN ceramic  were conducive to its better applications in electronic equipment.

Keywords: BNT-based ceramics, Antiferroelectric AgNbO3, Energy-storage properties, Dielectric performances, Fatigue resistance.