Mechanism of thermal conductivity suppression in doped silicon studied with nonequilibrium molecular dynamics

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.

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An Investigation on Thermal Conductivity of Fluid in a Nanochannel by Nonequilibrium Molecular Dynamics Simulations

Journal of Heat Transfer ◽

10.1115/1.4045750 ◽

2020 ◽

Vol 142 (3) ◽

Cited By ~ 2

Author(s):

Mohammad Bagheri Motlagh ◽

Mohammad Kalteh

Keyword(s):

Thermal Conductivity ◽

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Poiseuille Flow ◽

Driving Force ◽

Dynamics Simulation ◽

Nonequilibrium Molecular Dynamics ◽

Wall Roughness ◽

Dynamics Simulations ◽

Effect Of Copper

Abstract In this paper, molecular dynamics simulation is used to investigate the effect of copper and argon nanochannels size on the thermal conductivity of argon. Thermal conductivity is calculated by nonequilibrium molecular dynamics (NEMD) simulation. Simulations are performed for different distances between the walls. Results for both copper and argon walls are investigated individually. Results show that the existence of argon walls has little effect on the thermal conductivity. However, the amount of it for the argon confined between the copper walls is affected by the distance between the two walls. In the same way, the effect of wall roughness on the thermal conductivity is investigated, which shows that roughness is effective only for low distances between the walls. Also, the thermal conductivity of argon under Poiseuille flow in a nanochannel is studied. The results indicate that by increasing the driving force, the thermal conductivity increases and the increase ratio is higher for larger forces.

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Thermal Conductivity of Amorphous and Crystalline SiO2 Nano-Films from Molecular Dynamics Simulations

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.501.64 ◽

2012 ◽

Vol 501 ◽

pp. 64-69 ◽

Cited By ~ 1

Author(s):

Yan He ◽

Yuan Zheng Tang ◽

Man Ding ◽

Lian Xiang Ma

Keyword(s):

Thermal Conductivity ◽

Molecular Dynamics ◽

Film Thickness ◽

Molecular Dynamics Simulations ◽

Grain Morphology ◽

Nonequilibrium Molecular Dynamics ◽

Calculated Temperature ◽

Dynamics Simulations ◽

Different Thickness ◽

Good Agreement

Normal thermal conductivity of amorphous and crystalline SiO2nano-films is calculated by nonequilibrium molecular dynamics (NEMD) simulations in the temperature range from 100 to 700K and thicknesses from 2 to 6nm. The calculated temperature and thickness dependences of thermal conductivity are in good agreement with previous literatures. In the same thickness, higher thermal conductivity is obtained for crystalline SiO2nano-films. And more importantly, for amorphous SiO2nano-films, thickness can be any direction of x, y, z-axis without effect on the normal thermal conductivity, for crystalline SiO2nano-films, the different thickness directions obtain different thermal conductivity results. The different results of amorphous and crystalline SiO2nano-films simply show that film thickness and grain morphology will cause different effects on thermal conductivity.

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