The effect of A-site Mg substitution on energy-storage density and efficiency of Bi0.47Na0.47Ba0.06TiO3 ceramics by disordered induction

Lead-free dielectric ceramic capacitors are extensively studied for their environmental protection and excellent electrical properties. In this study, (1-x) Bi0.47Na0.47Ba0.06 TiO3-xMgTiO3 was synthesized by the classical solid -phase method. Perovskite materials usually have a complex structure, and the modification of the A-site and B -site doping can have a wonderful effect on the material. The effect of A-site Mg2+ doping on the phase structure and electrical properties of (1-x)BNBT-xMT was studied. Results showed that a wider optical band gap and a higher grain boundary density can be obtained by doping at the A-site, which greatly improved the breakdown electric field of the ceramics. X-ray diffraction, Raman scattering, transmission electron microscopy, and dielectric constant curves of (1-x)BNBT-xMT ceramics were also performed to characterize the transition be-tween rhombohedral and tetragonal phases. The findings indicated that that doping at the A-site successfully induced the polar nanoregion, and the 0.94Bi0.47Na0.47Ba0.06TiO3-0.06MgTiO3 relaxation ferroelectric ceramics had high Wrec (5.82 J/cm3), stable frequency (Wrec = 2.53 J/cm3 +/- 3 %, 1-200 Hz), excellent temperature sta-bility (Wrec approximate to 2.37 +/- 3 % J/cm3, 30-100 degrees C), and fast discharge rate (4 mu s). This work can provide ideas for the development of green and harmless dielectric capacitors with high charge/discharge rate and high energy-storage density.