**Equilibrium molecular dynamics simulations for the thermal conductivity
of Si/Ge nanocomposites**

XB Li and RG Yang, JOURNAL OF APPLIED PHYSICS, 113, 104306 (2013).

DOI: 10.1063/1.4794815

Various methods have been used to study the thermal conductivity of
nanocomposites which are playing increasing roles in energy conversion
and thermal management. However, when the size of particle inclusions is
on the order of several nanometers, the existing macro-and meso-scale
analytical methods cannot be used to predict the thermal conductivity of
nanocomposites due to the existence of both phonon wave interference and
particle scattering effects. In this study, equilibrium molecular
dynamics (EMD) is explored to study the thermal conductivity of Si/Ge
nanocomposites. We found that EMD can be used to study the thermal
conductivity of nanocomposites when multiple nanoparticles are included
to avoid the artificial effect of simulation domain sizes. We then
calculated the thermal conductivity of Si/Ge nanocomposites with
different volumetric ratio and particle size at 300 K. The result shows
that the thermal conductivity of Si/Ge nanocomposites first decreases
and then increases with decreasing particle size at fixed volumetric
ratio. The decreasing thermal conductivity is due to the increased
phonon scattering at high surface to volumetric ratio. When the particle
size is further reduced, the thermal conductivity recovers due to the
phonon wave interference effect. The effect of particle shape on the
thermal conductivity of Si/Ge nanocomposites is also studied. (C) 2013
American Institute of Physics. **http://dx.doi.org/10.1063/1.4794815**

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