Giant superstructures formed on graphite surface treated with NaOH solutions studied by scanning tunneling microscopy

Observation and investigation of graphite superlattice boundaries by scanning tunneling microscopy

“…This kind of zig-zag shaped boundary has been observed previously [2,11]. In all of these results, the zig-zag shaped boundaries appear to go around the superlattice bright spots rather than through them.…”

“…First, we will study the zig-zag shaped boundary. The zig-zag shaped boundary was discussed before and it was speculatively proposed that when the top graphite layer has a straight boundary, the observed superstructure which is induced by Moiré-type interference between the electronic wave-functions in adjacent grapheme layers must have a zig-zag shape at the boundary [11,23]. We have analyzed the zig-zag shaped boundary with a simulation model which can simulate graphite layers by using Eq.…”

“…According to Refs. [11,23], when the top rotated layer has a straight boundary, we should observe a zigzag shaped boundary with STM. In fact, we find experimentally that depending on its direction, the superlattice boundary does not necessarily have to intersect the bright spots.…”

“…Although superlattices on graphite have been observed many times by scanning tunnelling microscopy (STM) [1][2][3][4][5][6][7][8][9][10][11][12][13], a complete understanding has yet to be achieved as to their physical origins. Several theories and hypotheses ranging from Moiré interference patterns due to a mis-orientation of two layers of graphite, to sub-surface arrays of nanoscale defects have been proposed to explain the origin of superlattices [1,4,14,15].…”

The Role of Carboxylated Carbonaceous Fragments in the Functionalization and Spectroscopy of a Single‐Walled Carbon‐Nanotube Material

“…Aqueous alkali-metal hydroxide solutions have been reported to have graphite intercalation properties. [37,38] We therefore propose that NaOH intercalates p-stacked structures (e.g., graphitic impurities) in the sample during heating at 100°C. It seems likely that these p-stacked structures could get separated by the peptization of the intercalated NaOH to give a colloidal suspension in the water, which could be washed through the filter membrane, as observed.…”