The phenomenon of relaxor ferroelectrics is studied through detailed Raman spectroscopy on polycrystalline Sr_1-xPr_xTiO₃ (x = 0.01–0.17) samples. The polar mode was observed up to very high temperature ~1000 K indicating presence of dipoles well above the characteristic relaxor temperatures and they develop a short range correlation at 505 K leading to formation of PNRs. Below 505 K, the TO₂ polar mode anomalously soften along with Fano resonance and changes in the octahedral tilt angle. This establishes growth of local polar order associated with local structural phase transition at T ~505 K. The local TiO₆ octahedral tilt scales with the intensity of the polar mode and hence can be used as an order parameter for relaxor transition. It is shown that the paraelectric to relaxor ferroelectric phase transition in this compound is random polarizability instability driven phenomenon which has been correlated with the local octahedral tilt angle.

通过对多晶 Sr _{1- x} Pr _x TiO ₃ ( x  = 0.01–0.17) 样品的详细拉曼光谱研究弛豫铁电体现象。在高达~1000 K 的非常高的温度下观察到极性模式，表明偶极子的存在远高于特征弛豫温度，并且它们在 505 K 处形成短程相关性，导致 PNR 的形成。低于 505 K，TO ₂极模随着 Fano 共振和八面体倾斜角的变化而异常软化。这建立了与T ~505 K 的局部结构相变相关的局部极性顺序的增长。局部 TiO ₆八面体倾斜与极坐标模式的强度成比例，因此可用作弛豫跃迁的顺序参数。结果表明，该化合物中的顺电到弛豫铁电相变是随机极化不稳定性驱动的现象，与局部八面体倾斜角相关。