Chirality dependence of the thermal conductivity of carbon nanotubes

Zhang, Wei; Zhu, Zhiyuan; Wang, Feng; Wang, Tingtai; Sun, Litao; Wang, Zhenxia

doi:10.1088/0957-4484/15/8/010

Cited by 119 publications

(78 citation statements)

References 15 publications

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“…According to theoretical predictions via molecular-dynamics (MD) simulations, the thermal conductivity of CNTs along the tube axis at room temperatures is as high as that of diamond or graphite due to intermolecular strong covalent bonding [14][15][16][17][18][19][20][21][22]. In contrast, the thermal conductivity of CNTs perpendicular to the tube axis is very low because of the tube-tube weak coupling due to van der Waals interactions.…”

Section: Introductionmentioning

confidence: 99%

Molecular-dynamics simulations of thermal transport in carbon nanotubes with structural defects

Kondo

Yamamoto

Watanabe

2006

e-J. Surf. Sci. Nanotech.

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Effects of structural defects on thermal transport in carbon nanotubes are revealed through nonequilibrium molecular-dynamics simulations with the Tersoff-Brenner bond-order potential. The thermal conductivity of carbon nanotubes decreases rapidly down to 25 % with only 1 % vacancy defects. By performing thermal annealing, the vacancy defects are mainly transformed into 5-6 defects consisting of pentagon-hexagon pairs, and the reduced thermal conductivity due to vacancy defects is increased by 4-7 %. This improvement in thermal conductivity can be understood from the result that the thermal resistance of the 5-6 defects is smaller than that of the vacancy defects.

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Section: Introductionmentioning

confidence: 99%

Molecular-dynamics simulations of thermal transport in carbon nanotubes with structural defects

Kondo

Yamamoto

Watanabe

2006

e-J. Surf. Sci. Nanotech.

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“…A two-dimensional materials-graphene [2], in addition to its exceptional electric [3] and optical properties [4] , [5], reveals unique high thermal conductivity. Thermal conductivity of single-layer graphene as well as of carbon nanotubes is dependent on the chirality [6]. Recent theoretical studies suggest that the thermal conductivity of single-layer zigzag graphene is 20-50% larger than that of the singlelayer armchair graphene [7].…”

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confidence: 99%

Chirality and thickness-dependent thermal conductivity of few-layer graphene: A molecular dynamics study

Zhong

Zhang

et al. 2011

Applied Physics Letters

169

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The thermal conductivity of graphene nanoribbons (layer from 1 to 8 atomic planes) is investigated by using the nonequilibrium molecular dynamics method. We present that the room-temperature thermal conductivity decays monotonically with the number of the layers in few-layer graphene. The superiority of zigzag graphene in thermal conductivity is only available in high temperature region and disappears in multi-layer case. It is explained that the phonon spectral shrink in high frequency induces the change of thermal conductivity. It is also reported that single-layer graphene has better ballistic transport property than the multi-layer graphene.In the past decade, more and more attentions have been given to the question of what happens with thermal conductivity when goes to low-dimensional materials [1]. A two-dimensional materials-graphene [2], in addition to its exceptional electric [3] and optical properties [4] , [5], reveals unique high thermal conductivity. Thermal conductivity of single-layer graphene as well as of carbon nanotubes is dependent on the chirality [6]. Recent theoretical studies suggest that the thermal conductivity of single-layer zigzag graphene is 20-50% larger than that of the singlelayer armchair graphene [7]. However, whether the superior thermal conductivity of zigzag graphene remains available for multi-layer graphene has not got enough attention and concern.Additionally, experimental demonstrations have shown that the thermal conductivity gets a decrease at the twoto three-dimensional (2D to 3D) crossover of few-layer graphene [8]. The fact that the thermal conductivity of large enough graphene sheets should be higher than that of basal planes of bulk graphite was predicted theoretically by Klemens [9]. Generally, thermal transport in conventional thin films still retains 'bulk' features because the crosssections of these structures are measured in many atomic layers. Heat conduction in such nanostructures is dominated by extrinsic effects, for example, phonon-boundary or phonon-defect scattering [10]. A recent experimental observation of high-quality few-layer graphene materials shows that the room-temperature thermal conductivity changes from˜2,800 to˜1,300 Wm −1 K −1 when the number of atomic planes in few-layer graphene increases from 2 to 4. It is explained that the observed evolution from two dimensions to bulk attributed to the cross-plane coupling of the low-energy phonons and changes in the phonon Umklapp scattering [8].Recently, the method of molecular dynamics simulation has been successful in discovering thermal conductivity and thermal rectification of the nanostructures [7] , [11]. This method, which builds the system from the bottom up, is useful to understand the intrinsic behavior, i.e., the phonon spectral behavior behind the significant change of a material's ability to conduct heat [12]. In this paper, we will study the thermal conductivity of graphene ribbons (layer from 1 to 8 atomic planes) by using the nonequilibrium molecular dynamics method. By inve...

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“…Indeed, recent years have witnessed increasing interesting in thermal conductivity of nanotubes 8,9,10,11,12,13,14,15,16,17,18,19 , the questions raised here are still open.…”

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confidence: 99%

Thermal conductivity of nanotubes revisited: Effects of chirality, isotope impurity, tube length, and temperature

Zhang

2005

The Journal of Chemical Physics

303

211

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We study the dependence of thermal conductivity of single walled nanotubes (SWNT) on chirality, isotope impurity, tube length and temperature by nonequilibrium molecular dynamics method with accurate potentials. It is found that, contrary to electronic conductivity, the thermal conductivity is insensitive to the chirality. The isotope impurity, however, can reduce the thermal conductivity up to 60% and change the temperature dependence behavior. We also found that the tube length dependence of thermal conductivity is different for nanotubes of different radius at different temperatures.PACS numbers: 65.80+n, 66.70.+f, 44.10.+i Carbon nanotube is one of exciting nano-scale materials discovered in the last decade. It reveals many excellent mechanical, thermal and electronic properties 1 . Depends on its chirality 2,3 , the nanotube can be either metallic or semiconducting. For example, for zigzag (9,0) and (10,0) tubes, their radius are almost the same, but (9,0) tube behaves metallic and (10,0) tube semiconducting. At room temperature, the electronic resistivity is about 10 −4 − 10 −3 Ωcm for the metallic nanotubes, while the resistivity is about 10Ωcm for semiconducting tubes 4 . The 10% difference in radius induces the change of electronic conductivity in four orders of magnitude. One may ask, whether thermal conductivity is also very sensitive to the chirality like its electronic counterpart?On the other hand, the isotope impurity reduces thermal conductivity of most materials, such as germanium and diamond 5,6 . It is surprising that 1% 13 C in diamond leads to a reduction of thermal conductivity up to 30% 7 . Is there same effect in carbon nanotubes?Moreover, in electronic conductance, SWNT reveals many 1D characters 1 . However in thermal conduction, it is still not clear whether the conduction behavior is like that one of 1D lattice or a quasi 1D (1D lattice with transverse motions) or that one in a 2D lattice.These questions and many other relevant properties of nanotubes are very important and should be understood before the nanotubes are put into any practical application. Indeed, recent years have witnessed increasing interesting in thermal conductivity of nanotubes 8,9,10,11,12,13,14,15,16,17,18,19 , the questions raised here are still open.In this paper, we study the effects of the chirality, isotope impurity, tube length and temperature on SWNTs' thermal conductivity by using the nonequilibrium molecular dynamics (MD) method with bond order potential. This approach is valid as it shows that at finite temperature, phonon has a dominating contribution to thermal conduction than electron does 20,21 . We should pointed out that the thermal conductivity calculated in this paper is exclusively from lattice vibration. Of course, for the metallic nanotubes, the electrons may give some but limited contributions 20,21 , but this is not the main concern in our paper.The Hamiltonian of the carbon SWNT is:where] is the Tersoff empirical bond order potential. V R (r ij ), and V A (r ij ) are the repulsive and ...

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Chirality dependence of the thermal conductivity of carbon nanotubes

Cited by 119 publications

References 15 publications

Molecular-dynamics simulations of thermal transport in carbon nanotubes with structural defects

Molecular-dynamics simulations of thermal transport in carbon nanotubes with structural defects

Chirality and thickness-dependent thermal conductivity of few-layer graphene: A molecular dynamics study

Thermal conductivity of nanotubes revisited: Effects of chirality, isotope impurity, tube length, and temperature

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