Molecular Dynamics Calculation of Thermal Conductivity in A-Sio2 and an A-Sio2-based Nanocomposite

Thermal conductivity in amorphous SiO2 (alpha-SiO2) has been studied in a wide range of temperatures, by using the nonequilibrium molecular dynamics method and the Beest-Kramer-Santen, Tersoff, and Vashishta empirical potentials. The thermal conductivity of an alpha-SiO2-based composite with Si nanocrystals is calculated with the use of the Tersoff potential. The thermal conductivity of the nanocomposite is shown to firstly decrease and then to increase, as the silicon volumetric ratio grows. The obtained results are explained by the enhanced scattering of thermal vibrations at the matrix-Si nanocrystal boundaries.