Fig. 1. Temperature dependence of dielectric permittivity and dielectric loss for ceramics at different frequencies: (a) SBN40; (b) SBN50; (c) SBN60; (d) all of the samples at 1 kHz.陶瓷在不同频率下的介电常数和介电损耗与温度的关系　(a) SBN40; (b) SBN50; (c) SBN60; (d)所有样品在1 kHz频率下的介电常数和介电损耗与温度的关系

Fig. 2. The inverse of dielectric permittivity as a function of temperature at 1 kHz (the black solid lines are used to fit the Curie-Weiss law, the red solid lines used to fit the modified Curie-Weiss law): (a) SBN40; (b) SBN50; (c) SBN60; (d) the value of γ, T_m and T₀ for three samples at 1 kHz. 在1 kHz频率下, 介电常数与温度的函数关系(黑色实线是居里-外斯定律拟合, 红色实线是改进的居里-外斯定律的拟合)　(a) SBN40; (b) SBN50; (c) SBN60; (d)在1 kHz下三个样品的γ, T_m和T₀的值

Fig. 3. Cole-Cole plots for SBN ceramics (the insets show the normalized imaginary parts of impedance (Z''/Z''_max) with frequency): (a) SBN40; (b) SBN50; (c) SBN60; (d) Cole-Cole plots for SBN ceramics at 843 K. SBN陶瓷的Cole-Cole图(插图为阻抗虚部归一化 (Z''/Z''_max)随频率的变化关系图)　(a) SBN40; (b) SBN50; (c) SBN60; (d)在843 K下所有SBN陶瓷的Cole-Cole图

Fig. 4. (a) ln(ω) and (b) ln(σ) versus 1000/T curves for SBN ceramic with various Sr²⁺ concentrations. The straight lines were used to fit the Arrhenius law. (a) ln(ω) 和(b)ln(σ)对比具有各种Sr²⁺浓度的SBN陶瓷的1000/T曲线, 直线用于符合阿伦尼乌斯定律