Molecular dynamics simulation of thermal conductivity of thin diamond films

The heat conduction process in thin diamond film was simulated using non-equilibrium molecular dynamics method with Tersoff bond order potential. Heat flux through the film was controlled by the fixed boundary and constant heat flux techniques, and the thermal conductivity was calculated with Fourier's law from the heat flux and the temperature gradient in the film. The computational results showed that, in the microscale, the thermal conductivity varies linearly within the region of film thickness from 2 to 8 nm. For a given film thickness and heat flux, the thermal conductivity increases within temperature range from 400 K to 1200 K, and converges to a constant value when temperature increases up to 1200 K.