Thermal conductivity reduction in carbon nanotube by fullerene encapsulation: A molecular dynamics study

Abstract

Single-walled carbon nanotubes (SWCNTs) in their pristine form have high thermal conductivity whose further improvement has attracted a lot of interest. Some theoretical studies have suggested that the thermal conductivity of a $(10,10)$ SWCNT is dramatically enhanced by C${}_{60}$ fullerene encapsulation. However, recent experiments on SWCNT bundles show that fullerene encapsulation leads to a reduction rather than an increase in thermal conductivity. Here, we employ three different molecular dynamics methods to study the influence of C${}_{60}$ encapsulation on heat transport in a $(10,10)$ SWCNT. All the three methods consistently predict a reduction of the thermal conductivity of $(10,10)$ SWCNT upon C${}_{60}$ encapsulation by $20\%-30\%$, in agreement with experimental results on bundles of SWCNTs. We demonstrate that there is a simulation artifact in the Green-Kubo method which gives anomalously large thermal conductivity from artificial convection. Our results show that the C${}_{60}$ molecules conduct little heat compared to the outer SWCNT and reduce the phonon mean free paths of the SWCNT by inducing extra phonon scattering. We also find that the thermal conductivity of a $(10,10)$ SWCNT monotonically decreases with increasing filling ratio of C${}_{60}$ molecules.

arXiv comment26 pages, 10 figures

References in corpus (12)

• Optimized Tersoff and Brenner empirical potential parameters for lattice dynamics and phonon thermal transport in carbon nanotubes and graphene
• Force and heat current formulas for many-body potentials in molecular dynamics simulation with applications to thermal conductivity calculations
• Efficient molecular dynamics simulations with many-body potentials on graphics processing units
• Homogeneous nonequilibrium molecular dynamics method for heat transport and spectral decomposition with many-body potentials
• Frequency-dependent phonon mean free path in carbon nanotubes from non-equilibrium molecular dynamics
• Influence of Boundaries and Thermostatting on Nonequilibrium Molecular Dynamics Simulations of Heat Conduction in Solids
• Thermal conductivity decomposition in two-dimensional materials: Application to graphene
• Equivalence of the equilibrium and the nonequilibrium molecular dynamics methods for thermal conductivity calculations: From bulk to nanowire silicon
• Reduction of Phonon Lifetimes and Thermal Conductivity of a Carbon Nanotube on Amorphous Silica
• Heat transport in pristine and polycrystalline single-layer hexagonal boron nitride
• Thermal transport properties of single-layer black phosphorous from extensive molecular dynamics simulations
• Comparison of the Green-Kubo and homogeneous non-equilibrium molecular dynamics methods for calculating thermal conductivity

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