Prediction of the thermal conductivity of nanofilms

Abstract

Nanosequenced materials are used for several applications such as energy conversion and mechanical protection for carbon fibres in C/C composites submitted to high thermo-mechanical stresses. The performances of such materials strongly depend on their thermal conductivity. Specific experimental setups are required to measure the thermal conductivity of such material. These measurements are quite seldom and then prediction tools for the thermal conductivity of such materials are of great importance. We focus here on the thermal conductivity prediction of nanofilms. The model that has been developed is based on kinetic theory of gas (KT). The film in-plane and cross-plane thermal conductivity can be calculated. The model has been validated using experimental values of the in-plane thermal conductivity of Si nanofilms. The cross-plane values have been compared with two other models derived from the resolution of the Radiative Transfer Equation for phonons using Monte Carlo simulations and a Discrete Ordinates Method. The KT model is then applied to SiC.