The excellent functionalities of perovskite oxides and the growing demands for flexible devices lead to great interests on epitaxial growth of functional oxide films on flexible mica substrates. Understanding the film epitaxy on the substrate with a very different crystal structure is a key issue for the optimization of the film growth and hence properties. Such understanding largely depends on knowing the atomic structure of the interfaces between the films and the substrates. Here, the interface between the epitaxial films of SrTiO₃ on the fluorophlogopite mica substrate is studied in detail. Two types of interfaces, clean or with secondary phase, exist in this system, leading to two types of crystallographic orientation relationships. Atomic‐resolution scanning transmission electron microscopy images reveal that at the clean interface the (111) Sr–O₃ atomic plane of SrTiO₃ interacts with the (001) (SiAl)₂–O₃ plane of mica. This interface structure and thus the epitaxy of the film are understood in light of the strong similarity of the oxygen sublattices in these two atomic planes. First‐principles calculations demonstrate strong bonding of the atoms at the interface, which is also corroborated by the observation of misfit dislocations at the interfaces.

中文翻译：

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柔性云母基底上钙钛矿氧化物外延的原子尺度理解。

钙钛矿氧化物的优异功能性以及对柔性器件的需求不断增长，引起了人们对在柔性云母基板上功能性氧化物膜进行外延生长的兴趣。了解具有非常不同的晶体结构的基板上的薄膜外延是优化薄膜生长及其性能的关键问题。这种理解在很大程度上取决于对膜与基底之间界面的原子结构的了解。在此，SrTiO ₃的外延膜之间的界面对氟金云母在云母上的吸附作用进行了详细的研究。该系统中存在两种类型的界面，即纯相或具有第二相的界面，从而导致两种类型的晶体取向关系。原子分辨率扫描透射电子显微镜图像显示，在干净的界面上，SrTiO ₃的（111）Sr–O ₃原子平面与云母的（001）（SiAl）₂ –O ₃平面相互作用。鉴于氧气亚晶格在这两个原子平面中的强烈相似性，可以理解这种界面结构以及薄膜的外延。第一性原理计算证明了界面处原子的牢固键合，也通过观察界面处的失配位错得到了证实。