High-energy storage performance in lead-free (0.8-x)SrTiO3-0.2Na0.5Bi0.5TiO3-xBaTiO3 relaxor ferroelectric ceramics

lead-free (0.8-x)SrTiO3-0.2Na(0.5)Bi(0.5)TiO(3)-xBaTiO(3) ceramics (abbreviated as (0.8-x)ST-0.2NBT-xBT) were prepared by the conventional solid-state sintering method, and their crystal structure, dielectric properties, relaxor behavior and energy-storage property were investigated as a function of BT concentration. X-ray diffraction results reveal a pure perovskite structure with a pseudo-cubic phase. The dielectric measurements exhibit a relaxor behavior for all samples and the T-m gradually increases (from -49.67 degrees C to 67.91 degrees C) with increasing x. The pinched polarization-electric field (P-E) loops were observed in the samples with x <= 0.40 and the maximum polarization (P-m) increased from 11.37 mu C/cm(2) to 20.79 mu C/cm(2) at 8 kV/mm while x = 0.20-0.55. The maximum discharge energy-storage density (J(d)) (1.78 J/cm(3)) is obtained in x = 0.35 ceramic with a relatively high P-m (29.19 mu C/cm(2)) under an electric field of 17 kV/mm, which makes (0.8-x)ST-0.2NBT-xBT ceramics may be promising lead-free materials in practical high energy storage application. (C) 2018 Elsevier B.V. All rights reserved.