Abstract:
The Cu(111) surface is an important substrate for catalysis and the growth of 2D materials, but a comprehensive understanding of the preparation and formation of well-ordered and atomically clean Cu(111) surfaces is still lacking. In this work, the morphology and structure changes of the Cu(111) surface after treatment by ion bombardment and annealing with a temperature range of 300-720 °C are investigated systematically by using in situ low-temperature scanning tunneling microscopy. With the increase of annealing temperature, the surface morphology changes from corrugation to straight edge, the number of screw dislocations changes from none to numerous, and the surface atomic structure changes from disordered to ordered structures (with many reconstructions). In addition, the changing trend of step width and step height in different stages is different (first increased and then decreased). A perfect Cu(111) surface with a step height of one atom layer (0.21 nm) and a width of more than 150 nm was obtained. In addition, two interesting superstructures and a new surface phase with a large number of line defects were found. This work serves as a strong foundation for understanding the properties of Cu(111) surface, and it also provides important guidance for the effective pretreatment of Cu(111) substrates, which are widely used.
摘要:
Cu(111)表面是二维材料催化和生长的重要基底,但是仍然缺乏对有序和原子清洁的Cu(111)表面的制备和形成的全面了解。在这项工作中,使用原位低温扫描隧道显微镜系统地研究了离子轰击处理和300-720°C温度范围退火后Cu(111)表面的形貌和结构变化。随着退火温度的升高,表面形态从波纹变为直边,螺钉位错的数量从没有变为许多,表面原子结构从无序结构变为有序结构(具有许多重建)。此外,台阶宽度和台阶高度在不同阶段的变化趋势是不同的(先增大后减小)。获得具有一个原子层的台阶高度(0.21nm)和大于150nm的宽度的完美Cu(111)表面。此外,发现了两个有趣的上层结构和具有大量线缺陷的新表面相。这项工作为理解Cu(111)表面的性质奠定了坚实的基础,为Cu(111)衬底的有效预处理提供了重要指导,被广泛使用。