The Tube Length Dependence of Electronic Structures in Armchair Carbon Nanotubes - From the Standpoint of Topological Characteristics -

In this paper, we study the thermal conductivities of sing-walled carbon nanotubes (CNTs) and CNTs-based nanocomposites using molecular dynamics simulations. Length dependence of the thermal conductivity of (5, 5) carbon nanotube at 300 K and 1000 K is simulated. At room temperature the thermal conductivity shows linear length dependence with the tube length less than 40 nm, which indicates the completely ballistic transport. The thermal conductivity increases with the increase of the nanotube length, but the increase rate decreases as the length increases. It shows that the phonon transport transits from ballistic to diffusive. In the simulations, the power exponent of the thermal conductivity of carbon nanotube to the tube length decreases by decaying exponential function as the tube length increases. We also observe a decrease of the low-dimensional effects by the surrounding matters. A carbon-nanotube-atom-fixed and -activated scheme of non-equilibrium molecular dynamics simulations is put forward to extract the thermal conductivity of carbon nanotubes embedded in solid argon. Though a 6.5% volume fraction of CNTs increases the composite thermal conductivity by about twice larger than that of the pure basal material, the thermal conductivity of CNTs embedded in solids is found to be decreased by 1/8–1/5 with reference to that of pure ones. The decrease of the intrinsic thermal conductivity of the solid-embedded CNTs and the thermal interface resistance are demonstrated to be responsible for the results.

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The tube length dependence of topological resonance energy in armchair carbon nanotubes

Synthetic Metals ◽

10.1016/j.synthmet.2016.08.017 ◽

2016 ◽

Vol 221 ◽

pp. 176-178

Author(s):

D. Morikawa ◽

Y. Nomura ◽

N. Mizoguchi

Keyword(s):

Carbon Nanotubes ◽

Resonance Energy ◽

Tube Length ◽

Length Dependence ◽

Topological Resonance Energy

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The Quantum Length Dependence of Conductance in Molecular Device: An Ab Initio Study

Materials Science Forum ◽

10.4028/www.scientific.net/msf.663-665.519 ◽

2010 ◽

Vol 663-665 ◽

pp. 519-522

Author(s):

Cai Juan Xia ◽

Han Chen Liu ◽

Ying Tang Zhang

Keyword(s):

Electronic Transport ◽

First Principles ◽

Electronic Structures ◽

Density Functional ◽

Molecular Device ◽

Functional Theory ◽

Length Dependence ◽

Molecular Conductance ◽

Homo Lumo ◽

Molecular Compounds

By Applying Nonequilibrium Green’s Function Formalism Combined First-Principles Density Functional Theory, we Investigate the Electronic Transport Properties of Thiophene and Furan Molecules with Different Quantum Length. the Influence of HOMO-LUMO Gaps and the Spatial Distributions of Molecular Orbitals on the Electronic Transport through the Molecular Device Are Discussed in Detail. the Results Show that the Transport Behaviors Are Determined by the Distinct Electronic Structures of the Molecular Compounds. the Length Dependence of Molecular Conductance Exhibits its Diversity for Different Molecules.

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Formation Of Single-Wall Carbon Nanotubes Forrest Assemblies On Metal Surfaces

MRS Proceedings ◽

10.1557/proc-734-b5.4 ◽

2002 ◽

Vol 734 ◽

Author(s):

Debjit Chattopadhyay ◽

Izabela Galeska ◽

Fotios Papadimitrakopoulos

Keyword(s):

Carbon Nanotubes ◽

Surface Coverage ◽

Iron Hydroxide ◽

Growth Characteristics ◽

Self Organization ◽

Single Wall Carbon Nanotubes ◽

Unique Challenge ◽

Single Wall Carbon ◽

Topological Characteristics

ABSTRACTLearning how to purify and manipulate single wall carbon nanotubes (SWNTs) presents a unique challenge in material science. The processing-related difficulties of these long nano-fibers stem from their high aspect ratio, rigidity and the profound hydrophobic attractions along their tubular walls. Shortening them into discrete segments, with lengths from tens to hundreds of nanometers, presents a viable methodology to alleviate the shape-induced intractability. In addition, the metal-assisted self-organization of these nanosized objects into nano-forest geometries with dense perpendicular surface grafting, demonstrates that such nanosized objects hold significant promise for the development of nanoscale devices. This paper will present an extensive characterization of the topological characteristics of these assemblies, along with their surface coverage, growth characteristics and height fluctuation on iron hydroxide substrates.

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Geometries, electronic structures and energetics of small-diameter single-walled carbon nanotubes

Physica E Low-dimensional Systems and Nanostructures ◽

10.1016/j.physe.2010.07.025 ◽

2011 ◽

Vol 43 (3) ◽

pp. 669-672 ◽

Cited By ~ 9

Author(s):

Koichiro Kato ◽

Susumu Saito

Keyword(s):

Carbon Nanotubes ◽

Electronic Structures ◽

Small Diameter ◽

Single Walled Carbon Nanotubes ◽

Single Walled Carbon ◽

Walled Carbon Nanotubes

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STRUCTURAL AND ELECTRONIC PROPERTIES OF CARBON NANOTUBES

International Journal of Modern Physics C ◽

10.1142/s0129183100000158 ◽

2000 ◽

Vol 11 (01) ◽

pp. 175-182 ◽

Cited By ~ 15

Author(s):

ŞAKIR ERKOÇ

Keyword(s):

Carbon Nanotubes ◽

Electronic Properties ◽

Molecular Mechanics ◽

Density Of States ◽

Linear Dependence ◽

The Other ◽

Tube Length ◽

Single Wall Carbon Nanotubes ◽

Tube Size ◽

Structural And Electronic Properties

The structural and electronic properties of optimized open-ended single-wall carbon nanotubes with zigzag geometry have been investigated. The calculations were performed using molecular mechanics, extended Hückel, and AM1–RHF semiempirical molecular orbital methods. It has been found that the density of states of the zigzag model is sensitive to the tube size and changes as the tube length increases. On the other hand the energetics of the tube shows an almost linear dependence to the tube length, and a converging characteristics with respect to the number of hexagons forming the tube.

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