Molecular Dynamics Simulations of the Thermal Conductivity of Bismuth Telluride Using Two-Body Interatomic Potentials

2009 ◽  
Author(s):  
Bo Qiu ◽  
Xiulin Ruan
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Bismuth Telluride ◽  
Morse Potential ◽  
Energy Surface ◽  
Interatomic Potentials ◽  
Potential Form ◽  
Dynamics Simulations

Two-body interatomic potentials in the Morse potential form have been developed for bismuth telluride, and the potentials are used in molecular dynamics (MD) simulations to predict the thermal conductivity. The density functional theory with local density approximations is first used to calculate the total energies for many artificially distorted Bi2Te3 configurations to produce the energy surface. Then by fitting to this energy surface and other experimental data, the Morse potential form is parameterized. The fitted empirical interatomic potentials are shown to reproduce the elastic and phonon data well. Molecular dynamics simulations are then performed to predict the thermal conductivity of bulk Bi2Te3 at different temperatures, and the results agree with experimental data well.

Predicting Thermal Transport in Bi2Te3: From Bulk to Nanostructures

2011 ◽  
Vol 1329 ◽  
Author(s):  
Bo Qiu ◽  
Xiulin Ruan
Keyword(s):  
Experimental Data ◽  
Thin Films ◽  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Thermal Transport ◽  
Morse Potential ◽  
Density Functional ◽  
Energy Surface ◽  
Nanowire Diameter ◽  
Potential Form

ABSTRACTTwo-body interatomic potentials in the Morse potential form have been developed for bismuth telluride, and the potentials are used in molecular dynamics (MD) simulations to predict the thermal conductivity of Bi2Te3 bulk, nanowires and few-quintuple thin films. The density functional theory with local density approximations is first used to calculate the total energies for many artificially distorted Bi2Te3 configurations to produce the energy surface. Then by fitting to this energy surface and other experimental data, the Morse potential form is parameterized. Molecular dynamics simulations are then performed to predict the thermal conductivity of bulk Bi2Te3 at different temperatures, and the results agree with experimental data well. We also predicted the thermal conductivity of Bi2Te3 nanowires with diameter ranging from 3 to 30 nm with both smooth (SMNW) and rough (STNW) surfaces. It is found that when the nanowire diameter decreases to the molecular scale (below 10 nm, or the so called "quantum wire"), the thermal conductivity shows significant reduction as compared to bulk value. We find the dimensional crossover behavior of thermal transport in few quintuple layer (QL) thin films at room temperature, and we attribute it to the interplay between phonon Umklapp scattering and boundary scattering. Also, nanoporous films show significantly reduced thermal conductivity compared to perfect thin films, indicating that they can be very promising thermoelectric materials.

Thermal Conductivity of Solid Argon Nano-Films from Molecular Dynamics Simulations

2011 ◽  
Vol 221 ◽  
pp. 598-603 ◽  
Author(s):  
Lian Xiang Ma ◽  
Yuan Zheng Tang ◽  
Yan He
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Film Thickness ◽  
Computer Program ◽  
Molecular Dynamics Simulations ◽  
Film Plane ◽  
Nonequilibrium Molecular Dynamics ◽  
Dynamics Simulations ◽  
Solid Argon

Thermal conductivity of L-J potential solid argon nano-films is calculated by equilibrium molecular dynamics (EMD) and nonequilibrium molecular dynamics (NEMD) simulations in the temperature range from 30K to 80K. A LAMMPS computer program has been modified based on classical molecular dynamics. It can be directly used to calculate the thermal conductivity of nano-films in the direction perpendicular to the film plane. Thermal conductivity calculated from this program is compared with experimental data. It is found that this computer program is competent to calculate the thermal conductivity of solid nano-films. It is also found that thermal conductivity is dependent on the simulation temperature and film thickness.

scholarly journals Ballistic Heat Transport in Nanocomposite: The Role of the Shape and Interconnection of Nanoinclusions

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1982
Author(s):  
Paul Desmarchelier ◽  
Alice Carré ◽  
Konstantinos Termentzidis ◽  
Anne Tanguy
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Free Path ◽  
Mean Free Path ◽  
Strong Increase ◽  
Moderate Increase ◽  
Energy Propagation ◽  
The Mean ◽  
Dynamics Simulations

In this article, the effect on the vibrational and thermal properties of gradually interconnected nanoinclusions embedded in an amorphous silicon matrix is studied using molecular dynamics simulations. The nanoinclusion arrangement ranges from an aligned sphere array to an interconnected mesh of nanowires. Wave-packet simulations scanning different polarizations and frequencies reveal that the interconnection of the nanoinclusions at constant volume fraction induces a strong increase of the mean free path of high frequency phonons, but does not affect the energy diffusivity. The mean free path and energy diffusivity are then used to estimate the thermal conductivity, showing an enhancement of the effective thermal conductivity due to the existence of crystalline structural interconnections. This enhancement is dominated by the ballistic transport of phonons. Equilibrium molecular dynamics simulations confirm the tendency, although less markedly. This leads to the observation that coherent energy propagation with a moderate increase of the thermal conductivity is possible. These findings could be useful for energy harvesting applications, thermal management or for mechanical information processing.

scholarly journals Local Structuring of Diketopyrrolopyrrole (DPP)-based Oligomers from Molecular Dynamics Simulations

2021 ◽  
Author(s):  
Maryam Reisjalali ◽  
J. Javier Burgos-Marmol ◽  
Rex Manurung ◽  
Alessandro Troisi
Keyword(s):  
Experimental Data ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
High Mobility ◽  
Semiconducting Polymers ◽  
Microscopic Structure ◽  
Dynamics Simulations

The microscopic structure of high mobility semiconducting polymers is known to be essential for their performance but it cannot be easily deduced from the available experimental data. A series of...

A Molecular Dynamics Study of Thermal Conductivity in Nanocomposites via the Phonon Wave Packet Method

2009 ◽  
Author(s):  
Zhiting Tian ◽  
Sang Kim ◽  
Ying Sun ◽  
Bruce White
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Wave Packet ◽  
Molecular Dynamics Simulations ◽  
Phonon Scattering ◽  
Flow Direction ◽  
Normal Incidence ◽  
Material Interfaces ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations

The phonon wave packet technique is used in conjunction with the molecular dynamics simulations to directly observe phonon scattering at material interfaces. The phonon transmission coefficient of nanocomposites is examined as a function of the defect size, thin film thickness, orientation of interface to the heat flow direction. To generalize the results based on phonons in a narrow frequency range and at normal incidence, the effective thermal conductivity of the same nanocomposite structure is calculated using non-equilibrium molecular dynamics simulations for model nanocomposites formed by two mass-mismatched Ar-like solids and heterogeneous Si-SiCO2 systems. The results are compared with the modified effective medium formulation for nanocomposites.

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