New scanning tunneling microscopy technique enables systematic study of the unique electronic transition from graphite to graphene

Abstract

A series of measurements using a novel technique called electrostatic-manipulation scanning tunneling microscopy were performed on a highly-oriented pyrolytic graphite (HOPG) surface.The electrostatic interaction between the STM tip and the sample can be tuned to produce both reversible and irreversible large-scale vertical movement of the HOPG surface. Under this influence, atomic-resolution STM images reveal that a continuous electronic reconstruction transition from a triangular symmetry, where only alternate atoms are imaged, to a honeycomb structure can be systematically controlled. First-principles calculations reveal that this transition can be related to vertical displacements of the top layer of graphite relative to the bulk. Detailed analysis of the band structure predicts that a transition from parabolic to linear bands occurs after a 0.09 nm displacement of the top layer.

Electronic transition from graphite to graphene via controlled movement of the top layer with scanning tunneling microscopy

“…23 In this article, we present STM images of the HOPG surface before, during, and after perturbing the surface using a technique called electrostatic-manipulation STM (EM-STM). 24 -5-With this technique large-scale precision-controlled vertical movement of the graphite surface is possible. Atomic-scale STM images reveal a continuous transition from graphite to graphene.…”

Pressure-induced commensurate stacking of graphene on boron nitride

“…Here we demonstrate a path towards achieving control over this degree of freedom by demonstrating that pressure exerted by a scanning tunnelling microscope (STM) tip 16 17 18 19 20 is capable of compressing or relaxing the interlayer separation locally between graphene and hBN. We also show that by modulating the interlayer separation we can control the degree of local commensurate stacking and the in-plane strain of graphene.…”

Atomic-scale movement induced in nanoridges by scanning tunneling microscopy on epitaxial graphene grown on 4H-SiC(0001)

“…Previous studies have established that graphite derivatives, including graphene, are especially susceptible to movement induced by the electrostatic interaction between the STM tip and the sample. [42][43][44][45] In the simplest situation, constant-current scanning tunneling spectroscopy measurements used on freestanding graphene clearly demonstrated that the graphene flexes more than 30 nm toward the STM as the tip bias increases from 0.1 V to 3.0 V. 43 Using a similar technique on graphite, large scale movement of 20 nm wide ribbons was also demonstrated. 44 Another important example, on an insulating substrate, was done by Mashoff et.al, who demonstrated oscillatory motion induced in graphene on SiO2 using STM.…”

“…[42][43][44][45] In the simplest situation, constant-current scanning tunneling spectroscopy measurements used on freestanding graphene clearly demonstrated that the graphene flexes more than 30 nm toward the STM as the tip bias increases from 0.1 V to 3.0 V. 43 Using a similar technique on graphite, large scale movement of 20 nm wide ribbons was also demonstrated. 44 Another important example, on an insulating substrate, was done by Mashoff et.al, who demonstrated oscillatory motion induced in graphene on SiO2 using STM. 46 With the idea of independent sample movement in mind, we introduce a "sample creep" model to best explain our results.…”