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arXiv · 1907.02011

Intrinsic superstructure near atomically clean armchair-type step edge of graphite

Wenhan Zhang·Zheng Ju·Weida Wu
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Abstract

We investigated the electronic superstructure of graphite surface in the vicinity to monoatomic armchair step edges with scanning tunneling microscopy and spectroscopy. Only the ($\sqrt{3}\times\sqrt{3}$)$\textit{R}$30$^{\circ}$ 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 ($\sqrt{3}\times\sqrt{3}$)$\textit{R}$30$^{\circ}$ superstructure on both sides of the step edge. We have also visualized a mixture of ($\sqrt{3}\times\sqrt{3}$)$\textit{R}$30$^{\circ}$ and honeycomb superstructures near structurally defective armchair edges. Our results suggest that the honeycomb superstructure pattern results from superposition of two sets of ($\sqrt{3}\times\sqrt{3}$)$\textit{R}$30$^{\circ}$ superstructure with different phases. Our observation solves the mystery of the coexistence of two types of superstructures reported by prior studies.

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Wenhan Zhang, Zheng Ju, Weida Wu. 2019-07-03. Intrinsic superstructure near atomically clean armchair-type step edge of graphite. https://doi.org/10.1103/physrevb.100.115120

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