Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
Sci Rep. 2016 Dec 2;6:38168. doi: 10.1038/srep38168.
Direct observations using scanning transmission electron microscopy unveil an intriguing interfacial bi-layer that enables epitaxial growth of a strain-free, monoclinic, bronze-phase VO(B) thin film on a perovskite SrTiO (STO) substrate. We observe an ultrathin (2-3 unit cells) interlayer best described as highly strained VO(B) nanodomains combined with an extra (Ti,V)O layer on the TiO terminated STO (001) surface. By forming a fully coherent interface with the STO substrate and a semi-coherent interface with the strain-free epitaxial VO(B) film above, the interfacial bi-layer enables the epitaxial connection of the two materials despite their large symmetry and lattice mismatch.
通过使用扫描透射电子显微镜进行直接观察，揭示了一种有趣的界面双层结构，使得无应变的单斜青铜相 VO(B) 薄膜能够在钙钛矿 SrTiO (STO) 衬底上外延生长。我们观察到一个超薄（2-3 个单元）的界面层，最好描述为高度应变的 VO(B) 纳米域，与 TiO 终止的 STO（001）表面上的额外（Ti,V)O 层相结合。通过与 STO 衬底形成完全相干的界面以及与无应变外延 VO(B) 薄膜形成半相干界面，界面双层结构使得尽管两种材料具有较大的对称性和晶格失配，但仍能实现两种材料的外延连接。
