scholarly journals Molecular Dynamics Modeling of Thermal Conductivity of Silicon/Germanium Nanowires

2019 ◽  
Vol 19 (3) ◽  
pp. 222-225
Author(s):  
A. Kishkar ◽  
V. Kurylyuk
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Silicon Germanium ◽  
Nonequilibrium Molecular Dynamics ◽  
Dynamics Modeling ◽  
Si Nanowires ◽  
Germanium Nanowires ◽  
Molecular Dynamics Modeling ◽  
Phonon Spectra ◽  
Dynamics Method

The thermal conductivity of silicon/germanium nanowires with different geometry and composition has beenstudied by using the nonequilibrium molecular dynamics method. The thermal conductivity of the Si1-xGexnanowire is shown to firstly decrease, reaches a minimum at x=0.4 and then to increase, as the germaniumcontent x grows. It was found that in the tubular Si nanowires the thermal conductivity decreases monotonouslywith increasing radius of the cylindrical void. The phonon spectra were calculated and the mechanisms of phononscattering in the investigated nanowires were analyzed.

Molecular dynamics modeling of the thermal conductivity of irradiated SiC as a function of cascade overlap

2007 ◽  
Vol 101 (2) ◽  
pp. 023527 ◽  
Author(s):  
Jean-Paul Crocombette ◽  
Guillaume Dumazer ◽  
Nguyen Quoc Hoang ◽  
Fei Gao ◽  
William J. Weber
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Dynamics Modeling ◽  
Molecular Dynamics Modeling

Molecular Dynamics Modeling of Thermal Transport in Damaged Continua

2008 ◽  
Author(s):  
Navin Kumar ◽  
Kishore Pochiraju
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Dynamics Modeling ◽  
Damage State ◽  
Damage Propagation ◽  
Embedded Atom ◽  
Solid Gold ◽  
Change Behavior ◽  
Molecular Dynamics Modeling ◽  
Atomic Interactions

The interaction between the damage state and the thermal conductivity is studied in this paper. The damage propagation and the effective thermal conductivity of the damaged continuum is studied using equilibrium molecular dynamics (EMD) method based on the Green-Kubo relation. A solid gold lattice is considered and the damage is initiated and propagated by stretching two opposite ends while system is maintained at constant volume, constant temperature (NVT) condition. Both Lennard-Jones (LJ) 6–12 and embedded-atom method (EAM) potentials are used to model the inter-atomic interactions. Results are presented illustrating the load-displacement relationship during damage growth and the thermal conductivity change behavior for a selected crack length.

Thermal Performance Analysis of the Molecular Linkers in the Carbon Nanotube Composites under Stress Conditions

2013 ◽  
Vol 699 ◽  
pp. 179-183
Author(s):  
Jie He ◽  
Xiao Jin Zhang ◽  
Zhi Tao ◽  
Ye Xin Xu ◽  
Xi Wu
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Polymer Chain ◽  
Thermal Performance ◽  
Mean Free Path ◽  
Nonequilibrium Molecular Dynamics ◽  
Nanotube Composites ◽  
Deformation Ability ◽  
Carbon Nanotube Composites ◽  
Dynamics Method

The influence of the stress type, stress size and polymer chain number on the thermal performance of the molecular linker was investigated by the nonequilibrium molecular dynamics method (NEMD). The results demonstrate that the thermal conductivity of molecular linker first increases and then decreases with an increment in tension because of the interaction between the phonon mean free path and spectrum red-shifted of the molecular linker. While the molecular linker is in compression, the thermal conductivity is linear relationship with the magnitude of the force. With the length compressed to 90%, the thermal conductivity can be decreased 70% maximally. Moreover, increasing the polymer chain number can improve effectively the thermal performance and the anti-deformation ability of the molecular linker.

Thermal Conductivity of Hexagonal SiC Nanowire by Nonequilibrium Molecular Dynamics Simulations

2014 ◽  
Vol 487 ◽  
pp. 102-105
Author(s):  
Zan Wang ◽  
Hua Wei Guan ◽  
Ke Dong Bi
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Free Path ◽  
Density Functional ◽  
Mean Free Path ◽  
Nonequilibrium Molecular Dynamics ◽  
Functional Theory ◽  
Sic Nanowires ◽  
Dynamics Simulations ◽  
Dynamics Method

Using nonequilibrium Molecular Dynamics method, thermal properties of hexagonal 4H-SiC and 6H-SiC nanowires are investigated. The quantum errors between realistic temperatures and Molecular dynamics temperatures are rectified based on Density Functional Theory. Thermal conductivities of 4H-SiC and 6H-SiC nanowires are both simulated from 50K to 800K. The scale effect on the thermal conductivity of nanowire is also investigated by varying the nanowires length from 10nm to 130nm. Results indicate, if the length of phonon mean free path is shorter than that of nanowire, phonon-surface scattering will surpass boundary scattering to contribute thermal resistances. Therefore, the thermal conductivity of 4H-SiC or 6H-SiC nanowire is mainly determined by the comparability between the length of nanowires and phonon mean free path.

Molecular Dynamics Modeling of Heat Transport in Metals and Semiconductors

2010 ◽  
Author(s):  
Sreekant Narumanchi ◽  
Kwiseon Kim
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Thermal Transport ◽  
Hybrid Electric Vehicle ◽  
Heat Dissipation ◽  
Phonon Dispersion ◽  
Interfacial Resistance ◽  
Dynamics Modeling ◽  
Molecular Dynamics Modeling

Interfacial thermal transport is of great importance in a number of practical applications where interfacial resistance between layers is frequently a major bottleneck to effective heat dissipation. For example, efficient heat transfer at silicon/aluminum and silicon/copper interfaces is very critical in power electronics packages used in hybrid electric vehicle applications. It is therefore important to understand the factors that govern and impact thermal transport at semiconductor/metal interfaces. Hence, in this study, we use classical molecular dynamics modeling to understand and study thermal transport in silicon and aluminum, and some preliminary modeling to study thermal transport at the interface between silicon and aluminum. A good match is shown between our modeling results for thermal conductivity in silicon and aluminum and the experimental data. The modeling results from this study also match well with relevant numerical studies in the literature for thermal conductivity. In addition, preliminary modeling results indicate that the interfacial thermal conductance for a perfect silicon/aluminum interface is of the same order as experimental data in the literature as well as diffuse mismatch model results accounting for realistic phonon dispersion curves.

Molecular Dynamics Modeling of Thermal Conductivity of Engineering Fluids and Its Enhancement Due to Nanoparticle Inclusion

2006 ◽  
Author(s):  
C. B. Sobhan ◽  
Nithin Mathew ◽  
Rahul Ratnapal ◽  
N. Sankar
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Metallic Nanoparticles ◽  
Volume Fraction ◽  
Equations Of Motion ◽  
Thermal Conductivity Enhancement ◽  
Interatomic Potentials ◽  
Dynamics Modeling ◽  
Conductivity Enhancement ◽  
Molecular Dynamics Modeling

A theoretical methodology based on molecular dynamics modeling, for the estimation of the enhancement of the thermal conductivity of fluids by the introduction of suspended metallic nanoparticles is proposed here. This involves the process of generating the atomic trajectories of a system of a finite number of particles by direct integration of the classical Newton’s equations of motion, with appropriate interatomic potentials and application of suitable initial and boundary conditions. Algorithms are made for simulating the nanofluid abiding the procedural steps of the Molecular Dynamics method. The method is presented as a means to solve the generic problem of thermal conductivity enhancement of liquids in the presence of nanoparticles, and illustrated using a specific simulation procedure with properties representing water and platinum nanoparticles. The thermal conductivity enhancement in the base fluid due to suspension of nanoparticles, estimated using Molecular dynamics simulations are compared with existing experimental results and those predicted by conventional effective medium theories. Parametric studies are conducted to obtain the variation of thermal conductivity enhancement with the temperature, and the volume fraction of the nanoparticles in the suspension.

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