In the present work, the nature of phase evolution of (1−x)(Na_0.5Bi_0.5)TiO₃-xSrTiO₃ (NBT-xST) solid solutions with x of 0–0.6 is revealed by characterizing the dielectric and ferroelectric properties. Two unique dielectric anomalies associated with high-temperature nanoregions (PNRs) in the ergodic relaxor (ER) state and low-temperature PNRs in the nonergodic relaxor (NR) state are identified. Characteristic temperatures, including T_B, T_RT∗, T_m, T_d and T_T∗, are determined in fresh and poled states on the basis of the characteristics of the evolution of these two dielectric anomalies. The whole evolution of the transition from the NR state to the ER state is reflected by the temperature-dependent polarization versus electric field (P-E) hysteresis loops, i.e., from the square loops, via the double-like loops, to the slim loops. The characteristic temperatures, including T_P-N, T_N-R and T_R-dis, are determined by the characteristics of the evolution of P-E loops. Accordingly, a phase diagram of NBT-xST was constructed according to these characteristic temperatures. Most importantly, the relationship between polarization responses and heterogeneous polar phase coexistence has been established and a schematic diagram is given. This work will help to understand the phase evolution and its impact on the macroscopic properties of NBT and the associated NBT-based solid solutions.

在本工作中，通过介电和铁电的特性揭示了（1- x）（Na _0.5 Bi _0.5）TiO ₃ - x SrTiO ₃（NBT- x ST）固溶体的相演化性质，其x为0-0.6。属性。确定了与遍历弛豫（ER）状态的高温纳米区域（PNR）和非遍历弛豫（NR）状态的低温PNR相关的两个独特的介电异常。特征温度，包括T _B， T _{RT ∗}，T _m，T _d和T_T＊，是根据这两个介电异常的演化特征在新鲜和极化状态下确定的。从NR状态到ER状态过渡的整个过程反映在温度相关的极化对电场（ P - E）磁滞回线上，即从方形回线到双线性回线到细长循环。包括T _P-N， T _N-R和T _R-dis的特征温度由P - E环的演化特征决定。因此，NBT- x的相图根据这些特征温度构建ST。最重要的是，已经建立了极化响应和异相极性共存之间的关系，并给出了示意图。这项工作将有助于理解相变及其对NBT的宏观性能以及相关的基于NBT的固溶体的影响。