Lead-free (1 − x)BaTiO3–xBi(Zn2/3Nb1/3)O3 (x = 0.05–0.20) materials were fabricated via solid-state reactions. A pure perovskite pseudocubic structure is obtained for all compositions. Dielectric measurements reveal an intensified diffusion and relaxor-like characteristics from 5 mol% to 20 mol% Bi(Zn2/3Nb1/3)O3. Weakly coupled relaxor behavior is concluded from the exceptionally high activation energies of ∼0.20–0.22 eV from the Vogel–Fulcher model for x ≥ 0.10, which possibly results in the extremely low dielectric nonlinearity and extra slim polarization–electric field loops. An optimal discharged energy density of 0.79 J cm−3 with a high energy efficiency of 93.5% is achieved at 131 kV cm−1 for x = 0.15, which proves that the BaTiO3–Bi(Zn2/3Nb1/3)O3 material is a promising candidate for high energy storage applications.
The (1− x )BaTiO 3 – x Bi(Zn 2/3 Nb 1/3 )O 3 ( x = 0.01–0.30) ceramics were synthesized by solid-state reactions. The solubility limit was determined to be x = 0.20. A systematic structural transition from a tetragonal phase ( x ≤ 0.034), to a mixture of tetragonal and rhombohedral phases (0.038 ≤ x ≤ 0.20), and finally to a pseudocubic phase ( x ≥ 0.22) at room temperature was identified. Dielectric measurement revealed a ferroelectric ( x ≤ 0.04) to relaxor ( x ≥ 0.06) transition with permittivity peak broadening and flattening, which was further verified by Raman spectroscopy and differential scanning calorimetry (DSC). Activation energies obtained from the Vogel–Fulcher model displayed an increasing trend from ~0.03 eV for x ~ 0.05, to unusually high values (>0.20 eV) for the compositions with x ≥ 0.15. With the increase in Bi(Zn 2/3 Nb 1/3 )O 3 content, the polarization hysteresis demonstrated a tendency from high nonlinearity to sublinearity coupled with the reduction in remnant polarization and coervice field. The deconvolution of the irreversible/reversible polarization contribution was enabled by first-order reversal curve distributions, which indicates that the decreasing polarization nonlinearity with the increase in Bi(Zn 2/3 Nb 1/3 )O 3 concentration could be related with the change from the ferroelectric domain and domain wall contributions to the weakly coupled relaxor behaviors.
危险品化学品经营许可证（带存储）