The Effect of Rare-Earth Dopants on Dielectric Behavior and Energy Storage Performances of NBST-Based Relaxor Ferroelectric Ceramics

In this study, Na 0.3 Bi 0.38 Sr 0.28 TiO 3 –2 wt% Re 2 O 3 (abbreviated as NBST–Re; Re = La, Nd, Sm, Dy, Er, and Yb) ceramics were prepared by the conventional solid-state reaction method. The effect of different rare-earth dopants on the phase structure, microstructure, dielectric behavior, and energy storage performance (ESP) of NBST-Re ceramics was investigated. All the prepared ceramics exhibit dense microstructure and perovskite structure with the coexistence of rhombohedral ( R 3 c ) and tetragonal ( P 4 bm ) phases. The temperature-dependent dielectric constant and dielectric loss curves prove obvious relaxation behavior induced by rare-earth dopants. Notably, the best ESPs were realized in NBST–Yb ceramic with a recoverable energy density of 2.10 J/cm 3 and the corresponding efficiency of 70.45% at 200 kV/cm. Furthermore, excellent frequency and temperature stabilities support the prospect of NBST-Yb ceramic in energy storage.