Thermal Transport in Nanocrystalline Materials

In this work, thermal transport in nanocrystalline materials is studied using large-scale equilibrium molecular dynamics (MD) simulation. Nanocrystalline materials with different grain sizes are studied to explore how and to what extent the size of nanograins affects the thermal conductivity and specific heat. Substantial thermal conductivity reduction is observed and the reduction is stronger for nanocrystalline materials with smaller grains. On the other hand, the specific heat of nanocrystalline materials shows little change with the grain size. The simulation results are compared with the thermal transport in individual nanograins based on MD simulation. Further discussions are provided to explain the fundamental physics behind the observed thermal phenomena in this work.