We had investigated the pressure-induced phase transition phenomenon in the perovskite-like material Nd₂Ti₂O₇ compound. The structural and vibrational properties of a layered Nd₂Ti₂O₇ have been studied by means of X-ray diffraction and Raman spectroscopy at pressures up to 30 GPa. The gradual structural phase transition from the initial monoclinic P2₁ $\left(C_2^2\right)$ phase to the monoclinic P2 $\left(C_2^1\right)$ phase was observed at P ∼ 19 GPa. This pressure-induced phase transition is accompanied by anomalies in the pressure behavior of unit cell parameters and vibrational modes. The role of pressure application as a trigger for a significant rotation of the TiO₆ octahedra, alterations in interatomic distances, and the displacement of Nd atoms were discussed.

_{我们研究了类钙钛矿材料Nd 2} Ti ₂ O ₇化合物中压力诱导的相变现象。通过X射线衍射和拉曼光谱在高达30 GPa的压力下研究了层状Nd ₂ Ti ₂ O _{7的结构和振动特性。}从最初的单斜晶系P2 ₁逐渐发生结构相变 $\left(C_2^2\right)$单斜晶系P2相 $\left(C_2^1\right)$在P ∼ 19 GPa下观察到相 。这种压力引起的相变伴随着晶胞参数和振动模式的压力行为异常。讨论了施加压力作为 TiO ₆八面体显着旋转的触发因素、原子间距离的变化以及 Nd 原子位移的触发因素。