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Defect-related hysteresis in nanotube-based nano-electromechanical systems.

Tsetseris L, Pantelides ST - Nanoscale Res Lett (2011)

Bottom Line: This fact can enable several applications of MWCNTs as nano-electromechanical systems (NEMS).Key defect-related effects, namely, sudden energy changes and hysteresis, are identified, and their relevance to a host of MWCNT-based NEMS is highlighted.The results also demonstrate the dependence of these effects on defect clustering and chirality of DWCNT shells.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics, National Technical University of Athens, GR-15780 Athens, Greece. leont@mail.ntua.gr.

ABSTRACT
The electronic properties of multi-walled carbon nanotubes (MWCNTs) depend on the positions of their walls with respect to neighboring shells. This fact can enable several applications of MWCNTs as nano-electromechanical systems (NEMS). In this article, we report the findings of a first-principles study on the stability and dynamics of point defects in double-walled carbon nanotubes (DWCNTs) and their role in the response of the host systems under inter-tube displacement. Key defect-related effects, namely, sudden energy changes and hysteresis, are identified, and their relevance to a host of MWCNT-based NEMS is highlighted. The results also demonstrate the dependence of these effects on defect clustering and chirality of DWCNT shells.

No MeSH data available.


Related in: MedlinePlus

Energy variation during consecutive migration steps of a C SI in a (9,0)@(18,0) carbon nanotube. The arrows show the rate-limiting step that determines a diffusion barrier of about 1.6 eV.
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Figure 1: Energy variation during consecutive migration steps of a C SI in a (9,0)@(18,0) carbon nanotube. The arrows show the rate-limiting step that determines a diffusion barrier of about 1.6 eV.

Mentions: The most stable structure [25] for a single C SI in a (9,0)@(18,0) DWCNT is an inter-tube bridge. Figure 1 shows the energy variations that accompany the successive transformations which enable this defect to migrate between neighboring sites. The results were obtained by the elastic band method [29], an approach that typically provides [30,31] barriers in satisfactory agreement with experiments. The method simulates the so-called minimum-energy pathway of a process with a sequence of intermediate configurations termed images. The curve of Figure 1 includes three local-energy minima, related to structures that play a role in the diffusion of SI through sequential switches of its bonds with the inner and outer shells. The effective activation energy for migration is about 1.6 eV.


Defect-related hysteresis in nanotube-based nano-electromechanical systems.

Tsetseris L, Pantelides ST - Nanoscale Res Lett (2011)

Energy variation during consecutive migration steps of a C SI in a (9,0)@(18,0) carbon nanotube. The arrows show the rate-limiting step that determines a diffusion barrier of about 1.6 eV.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211306&req=5

Figure 1: Energy variation during consecutive migration steps of a C SI in a (9,0)@(18,0) carbon nanotube. The arrows show the rate-limiting step that determines a diffusion barrier of about 1.6 eV.
Mentions: The most stable structure [25] for a single C SI in a (9,0)@(18,0) DWCNT is an inter-tube bridge. Figure 1 shows the energy variations that accompany the successive transformations which enable this defect to migrate between neighboring sites. The results were obtained by the elastic band method [29], an approach that typically provides [30,31] barriers in satisfactory agreement with experiments. The method simulates the so-called minimum-energy pathway of a process with a sequence of intermediate configurations termed images. The curve of Figure 1 includes three local-energy minima, related to structures that play a role in the diffusion of SI through sequential switches of its bonds with the inner and outer shells. The effective activation energy for migration is about 1.6 eV.

Bottom Line: This fact can enable several applications of MWCNTs as nano-electromechanical systems (NEMS).Key defect-related effects, namely, sudden energy changes and hysteresis, are identified, and their relevance to a host of MWCNT-based NEMS is highlighted.The results also demonstrate the dependence of these effects on defect clustering and chirality of DWCNT shells.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics, National Technical University of Athens, GR-15780 Athens, Greece. leont@mail.ntua.gr.

ABSTRACT
The electronic properties of multi-walled carbon nanotubes (MWCNTs) depend on the positions of their walls with respect to neighboring shells. This fact can enable several applications of MWCNTs as nano-electromechanical systems (NEMS). In this article, we report the findings of a first-principles study on the stability and dynamics of point defects in double-walled carbon nanotubes (DWCNTs) and their role in the response of the host systems under inter-tube displacement. Key defect-related effects, namely, sudden energy changes and hysteresis, are identified, and their relevance to a host of MWCNT-based NEMS is highlighted. The results also demonstrate the dependence of these effects on defect clustering and chirality of DWCNT shells.

No MeSH data available.


Related in: MedlinePlus