The nexus between classic ferroelectricity and the structure of perovskite materials hinges on the concept of lattice disorder. Although the ordered perovskites display short-range displacements of the central cations around their equilibrium points, the lattice disorder dynamically unfolds to generate a myriad of distorted rhombohedral lattices characterized by the hopping of the central cations across <111> directions. It is discovered that the lattice disorder correlates with the emergence of minimum configuration energy <100> pathways for the central cations, resulting in spatially modulated ultrafast polarization nanocluster arrangements that are stabilized by the electric charge defects in the material. Through high-resolution phonon dispersion analyses encompassing molecular dynamics (MD) and density functional theory (DFT) simulations, we provide unequivocal evidence linking the hopping of central cations to the development of diffuse soft phonon modes observed throughout the phase transitions of the perovskite. Through massive MD simulations, we unveil the impact of lattice disorder on the structures of domain walls at finite-temperature vis-à-vis collective activation and deactivation of <100> pathways. Furthermore, our simulations demonstrate the development of hierarchical morphotropic phase boundary (MPB) nanostructures under the combined influence of externally applied pressure and stress relaxation, characterized by sudden emergence of zig-zagged monoclinic arrangements that involve dual <111> shifts of the central cations. These findings have implications for tailoring MPBs in thin-film structures and for the light-induced mobilization of DWs. Avenues are finally uncovered to the exploration of lattice disorder through gradual shear strain application.

经典铁电性和钙钛矿材料结构之间的联系取决于晶格无序的概念。尽管有序钙钛矿显示出中心阳离子在其平衡点附近的短程位移，但晶格无序动态展开，产生无数扭曲的菱形晶格，其特征是中心阳离子在<111>方向上跳跃。研究发现，晶格无序与中心阳离子的最小构型能<100>路径的出现相关，从而产生空间调制的超快极化纳米团簇排列，该排列通过材料中的电荷缺陷来稳定。通过包括分子动力学（MD）和密度泛函理论（DFT）模拟的高分辨率声子色散分析，我们提供了明确的证据，将中心阳离子的跳跃与在钙钛矿相变过程中观察到的扩散软声子模式的发展联系起来。通过大规模MD模拟，我们揭示了有限温度下晶格无序对畴壁结构的影响相对于<100> 通路的集体激活和失活。此外，我们的模拟证明了在外部施加的压力和应力松弛的综合影响下分层同形相界（MPB）纳米结构的发展，其特征是突然出现涉及中心阳离子双<111>位移的锯齿形单斜晶排列。这些发现对于在薄膜结构中定制 MPB 和 DW 的光诱导动员具有重要意义。最终通过逐渐施加剪切应变来探索晶格无序的途径。