Argonne National Laboratory, Argonne, IL 60439, USA.
ACS Nano. 2009 Dec 22;3(12):4132-6. doi: 10.1021/nn901086x.
Using cross-sectional scanning tunneling microscopy on in situ fractured SrTiO(3), one of the most commonly used substrates for the growth of complex oxide thin films and superlattices, atomically smooth terraces have been observed on (001) surfaces. Furthermore, it was discovered that fracturing this material at room temperature results in the formation of stripe patterned domains having characteristic widths ( approximately 10 to approximately 20 nm) of alternating surface terminations that extend over a long range. Spatial characterization utilizing spectroscopy techniques revealed a strong contrast in the electronic structure of the two domains. Combining these results with topographic data, we are able to assign both TiO(2) and SrO terminations to their respective domains. The results of this experiment reveal that fracturing this material leads to reproducibly flat surfaces that can be characterized at the atomic-scale and suggest that this technique can be utilized for the study of technologically relevant complex oxide interfaces.
使用原位断裂 SrTiO3(最常用于生长复杂氧化物薄膜和超晶格的衬底之一)的横截面扫描隧道显微镜,在(001)表面上观察到原子级光滑的梯台。此外,还发现,在室温下断裂这种材料会导致形成具有特征宽度(约 10 至约 20nm)的条纹图案化畴的形成,这些畴的表面终止交替延伸很长一段距离。利用光谱技术进行空间特征化揭示了两个畴之间电子结构的强烈对比。将这些结果与地形数据相结合,我们能够将 TiO2 和 SrO 终止分别分配给它们各自的畴。该实验的结果表明,断裂这种材料会导致可在原子尺度上进行特征化的可重复平坦表面,并表明该技术可用于研究与技术相关的复杂氧化物界面。