Revealing the epitaxial growth mechanism and the interfacial coupling effect between oxide films will help to build a “structure-property” bridge for the design of microelectronic devices. Here, the epitaxial growth mechanism and the interfacial coupling in Bi_0.5Na_0.5TiO₃/SrTiO₃ (BNT/STO) heterointerfaces are investigated by the aberration-corrected scanning transmission electron microscopy, which is synthesized by a hydrothermal method. The results illustrate that 4 mol/L NaOH leads to not only the epitaxial growth of the BNT film but also the mutual diffusion of elements. The uneven distribution of local elements in BNT films is observed and confirmed to impact the cation displacements of B-site and lattice distortion. However, the overall trend of B-site cation displacement at the BNT/STO heterointerfaces is dominated by the interfacial strain. Additionally, the oxygen octahedral tilt exhibits continuous tilt patterns of a⁰a⁰a⁰ - a⁻b°c⁻ - a⁰a⁰c⁻ - a⁰b⁻c⁻ - a⁻b⁻c⁻ from the substrate to BNT film due to the constraint of the substrate and presents a strong correlation with cation displacement. These results are helpful to understand the underlying atomic structures and physical properties of BNT epitaxial thin films.

揭示外延生长机制和氧化膜之间的界面耦合效应，将有助于为微电子器件的设计搭建一座“结构-性能”的桥梁。_{在这里，Bi 0.5} Na _0.5 TiO ₃ /SrTiO ₃中的外延生长机制和界面耦合(BNT/STO) 异质界面通过水热法合成的像差校正扫描透射电子显微镜进行研究。结果表明，4 mol/L NaOH 不仅会导致 BNT 薄膜的外延生长，还会导致元素的相互扩散。观察并证实 BNT 薄膜中局部元素的不均匀分布会影响 B 位的阳离子位移和晶格畸变。然而，BNT/STO 异质界面 B 位阳离子置换的总体趋势受界面应变支配。此外，氧八面体倾斜呈现出a ⁰ a ⁰ a ⁰ - a ⁻ b ° c ^{−的连续倾斜模式}- a ⁰ a ⁰ c ⁻ - a ⁰ b ⁻ c ⁻ - a ⁻ b ⁻ c ⁻由于基底的约束，从基底到 BNT 薄膜，与阳离子位移有很强的相关性。这些结果有助于理解 BNT 外延薄膜的基本原子结构和物理性质。