Molecular dynamics simulations for the prediction of thermal conductivity of bulk silicon and silicon nanowires: Influence of interatomic potentials and boundary conditions

2011 ◽  
Vol 110 (3) ◽  
pp. 034309 ◽  
Author(s):  
Carolina Abs da Cruz ◽  
Konstantinos Termentzidis ◽  
Patrice Chantrenne ◽  
Xavier Kleber
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Boundary Conditions ◽  
Molecular Dynamics Simulations ◽  
Silicon Nanowires ◽  
Interatomic Potentials ◽  
Bulk Silicon ◽  
Dynamics Simulations

Thermal Conductivity in Thin Silicon Nanowires with Rough Surfaces by Molecular Dynamics Simulations

2010 ◽  
Author(s):  
Xueming Yang ◽  
Albert C. To ◽  
Jane W. Z. Lu ◽  
Andrew Y. T. Leung ◽  
Vai Pan Iu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Silicon Nanowires ◽  
Rough Surfaces ◽  
Thin Silicon ◽  
Dynamics Simulations

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.

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.

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.

Size-Dependent Elasticity of Silicon Nanowires

2009 ◽  
Vol 60-61 ◽  
pp. 315-319 ◽  
Author(s):  
W.W. Zhang ◽  
Qing An Huang ◽  
H. Yu ◽  
L.B. Lu
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Silicon Nanowires ◽  
First Principles ◽  
Si Nanowires ◽  
Size Dependent ◽  
Reconstructed Surfaces ◽  
Strain Relationship ◽  
Dynamics Simulations ◽  
Good Agreement

Molecular dynamics simulations are carried out to characterize the mechanical properties of [001] and [110] oriented silicon nanowires, with the thickness ranging from 1.05nm to 3.24 nm. The nanowires are taken to have ideal surfaces and (2×1) reconstructed surfaces, respectively. A series of simulations for square cross-section Si nanowires have been performed and Young’s modulus is calculated from energy–strain relationship. The results show that the elasticity of Si nanowires is strongly depended on size and surface reconstruction. Furthermore, the physical origin of above results is analyzed, consistent with the bond loss and saturation concept. The results obtained from the molecular dynamics simulations are in good agreement with the values of first-principles. The molecular dynamics simulations combine the accuracy and efficiency.

Multiscale Simulations of Thermoelectric Properties of PBTE

2008 ◽  
Author(s):  
Bo Qiu ◽  
Hua Bao ◽  
Xiulin Ruan
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Thermoelectric Properties ◽  
Transport Coefficients ◽  
Multiscale Simulation ◽  
Full Potential ◽  
Boltzmann Transport ◽  
Pair Potentials ◽  
Dynamics Simulations

In this paper, thermoelectric properties of bulk PbTe are calculated using first principles calculations and molecular dynamics simulations. The Full Potential Linearized Augmented Plane Wave (FP-LAPW) method is first employed to calculate the PbTe band structure. The transport coefficients (Seebeck coefficient, electrical conductivity, and electron thermal conductivity) are then computed using Boltzmann transport equation (BTE) under the constant relaxation time approximation. Interatomic pair potentials in the Buckingham form are also derived using ab initio effective charges and total energy data. The effective interatomic pair potentials give excellent results on equilibrium lattice parameters and elastic constants for PbTe. The lattice thermal conductivity of PbTe is then calculated using molecular dynamics simulations with the Green-Kubo method. In the end, the figure of merit of PbTe is computed revealing the thermoelectric capability of this material, and the multiscale simulation approach is shown to have the potential to identify novel thermoelectric materials.

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