4.3.1 Thermal conductivity of graphite at room temperature

Uher, Ctirad

doi:10.1007/10031435_90

Cited by 3 publications

(2 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Precise measurements of thermal conductivity are very difficult, as witnessed by the reported thermal conductivity data in the basal plane of graphite [20] which show a scatter by nearly two orders of magnitude. Similar uncertainties have been associated with thermal conductivity measurements in "mats" of nanotubes [21].…”

Section: Thermal Conductivity Of Carbon Nanotubesmentioning

confidence: 99%

Electrical and thermal transport in carbon nanotubes

Tománek¹

2000

AIP Conference Proceedings

View full text Add to dashboard Cite

Abstract. Owing to their atomic-level perfection, carbon nanotubes exhibit unusually high electrical and thermal conductivity. Our electrical transport calculations, performed using a scattering technique based on the Landauer-Biittiker formalism, suggest that the conductance of inhomogeneous multi-wall nanotubes may show an unusual fractional quantization behavior, in agreement with recent experimental data. Our calculations also indicate that due to the combination of a large phonon mean free path, speed of sound and specific heat, the thermal conductivity of an isolated (10,10) carbon nanotube exceeds that of any known material, reaching the value A~6, 600 W /m·K at room temperature.

show abstract

Section: Thermal Conductivity Of Carbon Nanotubesmentioning

confidence: 99%

Electrical and thermal transport in carbon nanotubes

Tománek¹

2000

AIP Conference Proceedings

View full text Add to dashboard Cite

show abstract

“…In the experiment, the strong dependence of the thermal conductivity λ on l translates into an unusual sensitivity to isotopic and other atomic defects. This is best illustrated by the reported thermal conductivity values in the basal plane of graphite [6] which scatter by nearly two orders of magnitude. As similar uncertainties may be associated with thermal conductivity measurements in "mats" of nanotubes [4], we decided to determine this quantity using molecular dynamics simulations.…”

mentioning

confidence: 94%

Unusually High Thermal Conductivity in Carbon Nanotubes

Berber¹,

Savas²,

Kwon³

et al.

High Thermal Conductivity Materials

View full text Add to dashboard Cite

Combining equilibrium and non-equilibrium molecular dynamics simulations with accurate carbon potentials, we determine the thermal conductivity λ of carbon nanotubes and its dependence on temperature. Our results suggest an unusually high value λ≈6, 600 W/m·K for an isolated (10, 10) nanotube at room temperature, comparable to the thermal conductivity of a hypothetical isolated graphene monolayer or diamond. Our results suggest that these high values of λ are associated with the large phonon mean free paths in these systems; substantially lower values are predicted and observed for the basal plane of bulk graphite. 61.48.+c, 66.70.+f, 63.22.+m, 68.70.+w With the continually decreasing size of electronic and micromechanical devices, there is an increasing interest in materials that conduct heat efficiently, thus preventing structural damage. The stiff sp 3 bonds, resulting in a high speed of sound, make monocrystalline diamond one of the best thermal conductors [1]. An unusually high thermal conductance should also be expected in carbon nanotubes [2,3], which are held together by even stronger sp 2 bonds. These systems, consisting of seamless and atomically perfect graphitic cylinders few nanometers in diameter, are self-supporting. The rigidity of these systems, combined with virtual absence of atomic defects or coupling to soft phonon modes of the embedding medium, should make isolated nanotubes very good candidates for efficient thermal conductors. This conjecture has been confirmed by experimental data that are consistent with a very high thermal conductivity for nanotubes [4].In the following, we will present results of molecular dynamics simulations using the Tersoff potential [5], augmented by Van der Waals interactions in graphite, for the temperature dependence of the thermal conductivity of nanotubes and other carbon allotropes. We will show that isolated nanotubes are at least as good heat conductors as high-purity diamond. Our comparison with graphitic carbon shows that inter-layer coupling reduces thermal conductivity of graphite within the basal plane by one order of magnitude with respect to the nanotube value which lies close to that for a hypothetical isolated graphene monolayer.The thermal conductivity λ of a solid along a particular direction, taken here as the z axis, is related to the heat flowing down a long rod with a temperature gradient dT /dz bywhere dQ is the energy transmitted across the area A in the time interval dt. In solids where the phonon contribution to the heat conductance dominates, λ is proportional to Cvl, the product of the heat capacity per unit volume C, the speed of sound v, and the phonon mean free path l. The latter quantity is limited by scattering from sample boundaries (related to grain sizes), point defects, and by umklapp processes. In the experiment, the strong dependence of the thermal conductivity λ on l translates into an unusual sensitivity to isotopic and other atomic defects. This is best illustrated by the reported thermal conductivity values in the ba...

show abstract

Impact of Crystallinity on Relationship Between Electrical and Thermal Conductivities in Bulk Graphitic Materials

Badenhorst

2019

Int J Thermophys

View full text Add to dashboard Cite

4.3.1 Thermal conductivity of graphite at room temperature

Cited by 3 publications

References 37 publications

Electrical and thermal transport in carbon nanotubes

Electrical and thermal transport in carbon nanotubes

Unusually High Thermal Conductivity in Carbon Nanotubes

Impact of Crystallinity on Relationship Between Electrical and Thermal Conductivities in Bulk Graphitic Materials

Contact Info

Product

Resources

About