Charles University, Faculty of Mathematics and Physics, V Holešovičkách 2, Praha 8, Czech Republic.
Phys Rev Lett. 2012 Dec 28;109(26):266102. doi: 10.1103/PhysRevLett.109.266102. Epub 2012 Dec 26.
We adopt fringe counting from classical moiré interferometry on moiré patterns observed in scanning tunneling microscopy of strained thin films on single crystalline substrates. We analyze inhomogeneous strain distribution in islands of CeO2(111) on Cu(111) and identify a generic source of strain in heteroepitaxy--a thickness-dependent lattice constant of the growing film. This observation is mediated by the ability of ceria to glide on the Cu substrate. The moiré technique we are describing has a potential of nanometer-scale resolution of inhomogeneous two dimensional strain in incommensurate layered systems, notably in supported graphene.
我们采用在单晶衬底上的应变薄膜的扫描隧道显微镜中观察到的莫尔条纹中的经典云纹干涉条纹进行边缘计数。我们分析了 CeO2(111)在 Cu(111)上的岛状结构中的非均匀应变分布，并确定了异质外延中的一个通用应变源——生长膜的厚度相关晶格常数。这一观察结果是由氧化铈在 Cu 衬底上的滑移能力所介导的。我们所描述的莫尔技术具有在非共格层状系统中纳米级分辨率的不均匀二维应变的潜力，特别是在支撑的石墨烯中。
