Atomically Resolved Moiré Pattern of Graphene on Metal
A scanning tunneling microscope (STM) image with atom-level detail, showing a graphene-ruthenium layered surface with a moiré pattern. The surface is made by creating layers of ruthenium lattice, then adding a misaligned layer of graphene. The lower, darker areas indicate where the alignment of the graphene and ruthenium lattices brings their atoms closer together, allowing their electron clouds to strongly hybridize. The higher, brighter areas show where the alignment of the two lattices holds atoms further apart, weakening the hybridization so the surface is more similar to regular graphene. This patterning effect allows for fine control of the reactive behavior of 2D surfaces.
Oxygen Binding on Moiré Graphene
The 2D surface of a graphene-ruthenium moiré surface with bright atoms of oxygen adsorbed onto it. The layering of graphene and ruthenium creates a moiré effect that causes different areas of the surface to have different reactive behaviors. This provides a patterned template for the bright white oxygen atoms to attach to the surface. Such customized surfaces are promising platforms for quantum materials and catalysts.
Initial Stage of Faceting at the Atomic Level
Phase Separation of Self-Assembled Molecular Monolayer at the Atomic Level
The texture of this self-assembled monolayer, shown via atomic force micrograph, is the result of phase separation. The monolayer is made of two species, decanethiolate (C\(_{10}\)H\(_{21}\)S) and partially fluorinated decanethiolate (C\(_{10}\)H\(_4\)F\(_{17}\)S), which each stand nearly perpendicular to the gold surface underneath, but are immiscible with each other. This leads them to separate into small domains of one type or the other, which can be distinguished in this topographic image due to the 2 Ångstrom difference in their lengths. This kind of differentiation has great potential for the customization of surface properties.