Limits...
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 inter-tube sliding of a (6,6)@(11,11) carbon nanotube with a C SI (filled and open squares for sliding in opposite directions). The lines with almost vanishing values (filled circles) at the bottom are for the pristine case of no defects and for a single vacancy on the inner tube.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3211306&req=5

Figure 5: Energy variation during inter-tube sliding of a (6,6)@(11,11) carbon nanotube with a C SI (filled and open squares for sliding in opposite directions). The lines with almost vanishing values (filled circles) at the bottom are for the pristine case of no defects and for a single vacancy on the inner tube.

Mentions: When the inner shell is pulled with respect to the outer tube, the SI bridge is moving in the direction of sliding and the energy initially increases, as shown in the corresponding diagram of Figure 5. At a certain displacement, however, one of the bonds between the SI and the inner tube switches to a neighboring site and another cycle of stretching commences. The end result is that the SI stays roughly at the same spot during repeated cycles, despite the relative movement of the DWCNT tubes. When sliding materializes in the opposite direction, a different stretching sequence is traced, shown as open squares in Figure 5. This difference in paths gives rise to hysteresis during inter-tube sliding, highlighted by an arrow in Figure 5. Compared to the SI-related energy variation, the corresponding changes for a pristine (6,6)@(11,11) DWCNT or one with a single vacancy on the inner tube are negligible.


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

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

Energy variation during inter-tube sliding of a (6,6)@(11,11) carbon nanotube with a C SI (filled and open squares for sliding in opposite directions). The lines with almost vanishing values (filled circles) at the bottom are for the pristine case of no defects and for a single vacancy on the inner tube.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 5: Energy variation during inter-tube sliding of a (6,6)@(11,11) carbon nanotube with a C SI (filled and open squares for sliding in opposite directions). The lines with almost vanishing values (filled circles) at the bottom are for the pristine case of no defects and for a single vacancy on the inner tube.
Mentions: When the inner shell is pulled with respect to the outer tube, the SI bridge is moving in the direction of sliding and the energy initially increases, as shown in the corresponding diagram of Figure 5. At a certain displacement, however, one of the bonds between the SI and the inner tube switches to a neighboring site and another cycle of stretching commences. The end result is that the SI stays roughly at the same spot during repeated cycles, despite the relative movement of the DWCNT tubes. When sliding materializes in the opposite direction, a different stretching sequence is traced, shown as open squares in Figure 5. This difference in paths gives rise to hysteresis during inter-tube sliding, highlighted by an arrow in Figure 5. Compared to the SI-related energy variation, the corresponding changes for a pristine (6,6)@(11,11) DWCNT or one with a single vacancy on the inner tube are negligible.

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