We investigated the electronic superstructure of a graphite surface in the vicinity of monoatomic armchair step edges with scanning tunneling microscopy and spectroscopy. Only the (3×3)R30â superstructure is visualized near atomically clean armchair edges, while the honeycomb superstructure is absent. The spectroscopic mapping near the clean armchair edge clearly reveals the (3×3)R30â superstructure on both sides of the step edge. We have also visualized a mixture of (3×3)R30â and honeycomb superstructures near structurally defective armchair edges. Our results suggest that the honeycomb superstructure pattern results from a superposition of two sets of (3×3)R30â superstructures with different phases. Our observation solves the mystery of the coexistence of two types of superstructures reported by prior studies.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics