Interpretation of scanning tunneling microscope images showing anomalous periodic structures

Sawamura, Makoto; Womelsdorf, J. F.; Ermler, Walter C.

doi:10.1021/j100175a074

Cited by 12 publications

(5 citation statements)

References 2 publications

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“…However, images having two domains showing both normal atomic resolution and long-range periodicities along the grain boundaries lie beyond the explanation given using the multiple tip effect model (figure 2(a) in [57]). It is rather improbable that two minitips resolving an atomic lattice contribute the same amount to the tunnelling current.…”

Section: Multiple Tip Effectmentioning

confidence: 57%

“…If the multiple tips lie in more than one grain domain with different orientations of the atomic lattices simultaneously, the Moiré pattern would arise and result in the observed superlattice structure on the graphite surface under STM. However, images having two domains showing both normal atomic resolution and long-range periodicities along the grain boundaries lie beyond the explanation given using the multiple tip effect model (figure 2(a) in [57]). It is rather improbable that two minitips resolving an atomic lattice contribute the same amount to the tunnelling current.…”

Section: Multiple Tip Effectmentioning

confidence: 57%

“…As such, it was shown that the anomalous phenomenon of the superlattice around a screw dislocation is likely to be due to the varying rotation angle of the graphite layer around the screw dislocation. Bernhardt et al [52] and Sawamura et al [57] also observed superlattice structures with varying periodicities. However, the variations were along one direction rather than circulated around a screw dislocation.…”

Section: Simulation Model For Investigating Superlatticementioning

confidence: 92%

“…It is possible to take the tip shape and the tip-sample distance into consideration and integrate them with the simulation model. First used by Sawamura et al [57] in the three-dimensional simulation for the experimental STM image on the superlattice based on the rotation angle of the crystal axis of the tip with respect to the substrate crystal axis, this equation (equation ( 11)) defines the tunnelling current as the summation of currents due to tunnelling from each atom on the tip to every atom of the sample surface. The current intensity between an atom on the surface and an atom at the tip is described by the Tersoff and Hamann relation in the low bias limit [65].…”

Section: Simulation Model For Investigating Superlatticementioning

confidence: 99%

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A review and outlook for an anomaly of scanning tunnelling microscopy (STM): superlattices on graphite

Pong

Durkan²

2005

J. Phys. D: Appl. Phys.

159

127

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Since its invention in 1981, scanning tunnelling microscopy (STM) is well-known for its supreme imaging resolution enabling one to observe atomic-scale structures, which has led to the flourishing of nanoscience. As successful as it is, there still remain phenomena which are observed using STM but are beyond our understanding. Graphite is one of the surfaces which have been most extensively studied using STM. However, there are a number of unusual properties of graphite surfaces. First reported in the 1980s, superlattices on graphite have since been observed many times and by many groups, but as yet our understanding of this phenomenon is quite limited. Most of the observed superlattice phenomena are widely believed to be the result of a Moiré rotation pattern, arising from the misorientation between two graphite layers, as verified experimentally. A Moiré pattern is a lattice with larger periodicity resulting from the overlap of two lattices with smaller periodicities. As graphite layers are composed of hexagonal lattices with a periodicity of 0.246 nm, as observed using STM, when there are misoriented graphite layers overlapping each other, a Moiré pattern with larger periodicity, depending on the misorientation angle, will be produced and appear as a superperiodic hexagonal structure on top of the graphite atomic lattice of the topmost surface layer. It is important to study graphite superlattices because, firstly, knowledge of this phenomenon will enable us to properly interpret STM images; secondly, it helps us to understand the correlation between electronic structures and atomic-structure rearrangement of graphite which is of tremendous aid for engineering material properties; thirdly, and perhaps most importantly, the observation of the phenomenon exhibits the capability of STM to produce images indicating the nature of internal defects which are below the surface. Over recent years, experimental and modelling techniques have been developed to study this anomalous regime of STM; however, there is a lack of a systematic classification of this scattered information. This review article thus serves the purpose of organizing all these results so as to enable a more comprehensive understanding of this phenomenon. We review the discovery of graphite superlattices, the observation of the associated properties, and the research efforts on this subject. An effort is made to envision the future experimental and theoretical research possibilities to unveil the mystery of this anomaly of STM. Applications of graphite superlattices are also proposed.

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Section: Multiple Tip Effectmentioning

confidence: 57%

Section: Multiple Tip Effectmentioning

confidence: 57%

Section: Simulation Model For Investigating Superlatticementioning

confidence: 92%

Section: Simulation Model For Investigating Superlatticementioning

confidence: 99%

See 2 more Smart Citations

A review and outlook for an anomaly of scanning tunnelling microscopy (STM): superlattices on graphite

Pong

Durkan²

2005

J. Phys. D: Appl. Phys.

159

127

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“…3. 20 In the present study, however, such eventualities are ruled out as an origin for this superstructure because exactly the same superstructure is observed in a number of intercalated domains on a film and also on different films. 20 In the present study, however, such eventualities are ruled out as an origin for this superstructure because exactly the same superstructure is observed in a number of intercalated domains on a film and also on different films.…”

Section: Superstructure In Intercalated Domainsmentioning

confidence: 54%

Superstructure and boundary structure in stage 4 MoCl₅–graphite intercalation compounds studied by atomic force microscopy and scanning tunneling microscopy

et al. 1999

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Intercalated domains on stage 4 MoCl 5 -graphite intercalation compounds (MoCl 5 -GIC's) were observed by atomic force microscopy (AFM) and scanning tunneling microscopy (STM). On large intercalated domains, a superstructure was found, in relation with a modulation of the electronic properties of the first layer of carbon. From that, the structure of the chloride ions layer was discussed and a model including dimer molecules was proposed. At the boundaries between large intercalated and nonintercalated domains, corrugations were observed along certain crystallographic directions of graphite. Their morphology was studied in detail at atomic scale and formation mechanisms were proposed. Small intercalated domains were also observed. Their shapes were irregular but their boundaries were clear cut.270

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Graphite — A Unique Host Lattice

Schlögl¹

1994

Physics and Chemistry of Materials With Low-Dimensional Structures

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Interpretation of scanning tunneling microscope images showing anomalous periodic structures

Cited by 12 publications

References 2 publications

A review and outlook for an anomaly of scanning tunnelling microscopy (STM): superlattices on graphite

A review and outlook for an anomaly of scanning tunnelling microscopy (STM): superlattices on graphite

Superstructure and boundary structure in stage 4 MoCl₅–graphite intercalation compounds studied by atomic force microscopy and scanning tunneling microscopy

Graphite — A Unique Host Lattice

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Interpretation of scanning tunneling microscope images showing anomalous periodic structures

Cited by 12 publications

References 2 publications

A review and outlook for an anomaly of scanning tunnelling microscopy (STM): superlattices on graphite

A review and outlook for an anomaly of scanning tunnelling microscopy (STM): superlattices on graphite

Superstructure and boundary structure in stage 4 MoCl5–graphite intercalation compounds studied by atomic force microscopy and scanning tunneling microscopy

Graphite — A Unique Host Lattice

Contact Info

Product

Resources

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Superstructure and boundary structure in stage 4 MoCl₅–graphite intercalation compounds studied by atomic force microscopy and scanning tunneling microscopy