Remarkably minimized domain and elevated energy storage properties in Na0.48Bi0.48Ba0.04TiO3-based relaxor antiferroelectrics by interposing Bi(Mg2/3Ta1/3)O3

Abstract

Lead-free dielectric capacitors have been embraced recently due to their tiny volume, large energy density and superfast charge–discharge speed. Here, a recoverable energy storage density of ∼ 10.73 J cm−3 and an efficiency of ∼ 80.5% were simultaneously revealed in traditional sintering (1 − x) (Na0.48Bi0.48Ba0.04TiO3)-xBi(Mg2/3Ta1/3)O3 (x = 0.16) ceramics (BNBT-0.16BMT) under an applied electric field of 540 kV cm−1 via disordering B-site ions and modifying the B-site cation ratio. Specifically, the disorder of B-site ions was found to alter the crystal structure, delaying maximum polarization. Phase switching between rhombohedral and tetragonal was characterized with transmission electron microscopy, Raman scattering and dielectric constant curves. Mg/Ta dopant was shown to cause electric charge mismatch and change dielectric anomaly peaks, leading to a large maximum polarization value. Finally, BNBT-0.16BMT stabilizes the relaxor antiferroelectrics (RAFE) system, with a significant broad frequency (0.5–120 Hz), broad temperature stability (20–160 °C), and excellent discharge performance (WD ∼ 5.23 J cm−3; Ea ∼ 350 kV cm−1). This preparation shows potential for broad application in dielectric capacitors.