Temperature-dependent thermal conductivity of bent carbon nanotubes by molecular dynamics simulation

2011 ◽  
Vol 109 (10) ◽  
pp. 104316 ◽  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Dynamics Simulation ◽  
Temperature Dependent ◽  
Temperature Dependent Thermal Conductivity

Thermal properties of pillared-graphene nanostructures

2015 ◽  
Vol 1727 ◽  
Author(s):  
M. Rifu ◽  
K. Shintani
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Thermal Properties ◽  
Molecular Dynamics Simulation ◽  
Dynamics Simulation ◽  
Nonequilibrium Molecular Dynamics ◽  
Nonequilibrium Molecular Dynamics Simulation ◽  
Thermal Conductivities ◽  
Graphene Nanostructures

ABSTRACTThe thermal conductivities of pillared-graphene nanostructures (PGNSs) are obtained using nonequilibrium molecular-dynamics simulation. It is revealed their thermal conductivities are much smaller than the thermal conductivities of carbon nanotubes (CNTs). This fact is explained by examining the density of states (DOS) of the local phonons of PGNSs. It is also found the thermal conductivity of a PGNS linearly decreases with the increase of the inter-pillar distance.

Thermal Conductivity of Individual Single-Wall Carbon Nanotubes

2006 ◽  
Vol 129 (6) ◽  
pp. 705-716 ◽  
Author(s):  
Jennifer R. Lukes ◽  
Hongliang Zhong
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Dynamics Simulation ◽  
Single Wall Carbon Nanotubes ◽  
Heat Current ◽  
Single Wall Carbon ◽  
Simulation Methodology

Despite the significant amount of research on carbon nanotubes, the thermal conductivity of individual single-wall carbon nanotubes has not been well established. To date only a few groups have reported experimental data for these molecules. Existing molecular dynamics simulation results range from several hundred to 6600 W∕m K and existing theoretical predictions range from several dozens to 9500 W∕m K. To clarify the several-order-of-magnitude discrepancy in the literature, this paper utilizes molecular dynamics simulation to systematically examine the thermal conductivity of several individual (10, 10) single-wall carbon nanotubes as a function of length, temperature, boundary conditions and molecular dynamics simulation methodology. Nanotube lengths ranging from 5 nm to 40 nm are investigated. The results indicate that thermal conductivity increases with nanotube length, varying from about 10 W∕m to 375 W∕m K depending on the various simulation conditions. Phonon decay times on the order of hundreds of fs are computed. These times increase linearly with length, indicating ballistic transport in the nanotubes. A simple estimate of speed of sound, which does not require involved calculation of dispersion relations, is presented based on the heat current autocorrelation decay. Agreement with the majority of theoretical/computational literature thermal conductivity data is achieved for the nanotube lengths treated here. Discrepancies in thermal conductivity magnitude with experimental data are primarily attributed to length effects, although simulation methodology, stress, and intermolecular potential may also play a role. Quantum correction of the calculated results reveals thermal conductivity temperature dependence in qualitative agreement with experimental data.

Thermal Conductivity of Single-Wall Carbon Nanotubes

2004 ◽  
Author(s):  
Hongliang Zhong ◽  
Jennifer R. Lukes
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Dynamics Simulation ◽  
Tube Length ◽  
Single Wall Carbon Nanotubes ◽  
Single Wall Carbon ◽  
Simulation Methodology

Despite the significant amount of research on single-wall carbon nanotubes, their thermal conductivity has not been well established. To date only one experimental thermal conductivity measurement has been reported for these molecules around room temperature, with large uncertainty in the thermal conductivity values. Existing theoretical predictions based on molecular dynamics simulation range from several hundred to 6600 W/m-K. In an attempt to clarify the order-of magnitude discrepancy in the literature, this paper utilizes molecular dynamics simulation to systematically examine the thermal conductivity of several (10, 10) single-wall carbon nanotubes as a function of length, temperature, boundary conditions and molecular dynamics simulation methodology. The present results indicate that thermal conductivity ranges from about 30–300 W/m-K depending on the various simulation conditions. The results are unconverged and keep increasing at the longest tube length, 40 nm. Agreement with the majority of literature data is achieved for the tube lengths treated here. Discrepancies in thermal conductivity magnitude with experimental data are primarily attributed to length effects, although simulation methodology, stress, and intermolecular potential may also play a role. Quantum correction of the calculated results reveals thermal conductivity temperature dependence in qualitative agreement with experimental data.

Thermal Conductivity of Carbon Nanotubes With Defects

2011 ◽  
Author(s):  
Haibin Chen ◽  
Alan J. H. McGaughey
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Thermal Management ◽  
Direct Application ◽  
Dynamics Simulation ◽  
Fourier Law ◽  
Pristine Cnts ◽  
Thermal Conductivities

The high thermal conductivities of carbon nanotubes (CNTs) measured experimentally and predicted from theory suggest that they are good candidates for next-generation thermal management materials. The quantities of CNTs needed in applications preclude the use of pristine products. Limited work, however, has been done to study thermal transport in CNTs with defects. In this paper, the thermal conductivities of pristine CNTs and CNTs with various defect types (adatoms, single vacancies, double vacancies, and Stone-Wales) are systematically predicted using molecular dynamics simulation and a direct application of the Fourier law. We investigate the correlation between the thermal conductivity and defect energy.

The Thermal Conductivity of Magnesite, Dolomite and Calcite as Determined by Molecular Dynamics Simulation

2018 ◽  
Vol 19 ◽  
pp. 18-34 ◽  
Author(s):  
Leila Momenzadeh ◽  
Behdad Moghtaderi ◽  
Xian Feng Liu ◽  
Scott William Sloan ◽  
Irina V. Belova ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Long Range ◽  
Experimental Studies ◽  
Dynamics Simulation ◽  
Heat Current ◽  
Phonon Modes ◽  
Temperature Dependent ◽  
Potential Parameters

In this study, the phonon-based thermal conductivity of magnesite (MgCO3) and dolomite (CaMg(CO3)2) is calculated and compared with an earlier recent calculation on calcite (CaCO3). Equilibrium molecular dynamics simulation by way of the elegant Green-Kubo formalism is used for calculating the thermal conductivity. The thermal conductivity is investigated over a wide temperature range (from 200 K to 800 K) for all of the above mentioned materials. The most reliable potential parameters are used for characterising the interatomic interactions. In all of the models, two independent mechanisms are considered. The first is temperature independent, which is relevant to the acoustic short-range and optical phonons, and the other is temperature dependent, which is linked to the acoustic long-range phonons. In the study, the heat current autocorrelation function (HCACF) is calculated over the averages of the NPT, NVT and NVE ensembles in the x- and z- directions. In addition, it is shown that the optical, acoustic short- and long-range phonon modes are the main contributors to the decomposition model of the thermal conductivity. In a further investigation, the effects of the computational cell sizes on the thermal conductivity are investigated with five different simulation blocks containing 30, 240, 810, 1920 and 6480 atoms. Finally, this research provides a comparison of the thermal conductivity from this study and experimental studies: they are in good agreement.

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