The Study on Thermal Conductivities of Thin Films of Diamond-like Carbon by Molecular Dynamics Simulation

It is very important to investigate the thermal properties of thin films of diamond-like carbon (DLC) to accurately develop heat transfer model of the multi-layered structure of hard disk driver (HDD) under heat-assisted magnetic recording (HAMR) condition. The present study develops the models of DLC thin films and predicts their out-of-plane thermal conductivities by the molecular dynamics simulations. Particularly, the DLC models with different densities are obtained by the quenching process with an improved Tersoff potential with extended cutoff. The trend for the variation of DLC density with the sp³ content is consistent with those reported in the literature. The out-of-plane thermal conductivities of diamond and DLC thin films are calculated by the non-equilibrium molecular dynamics simulations. The former increases with the effective thermal conduction length while decreases with rising temperature in the range of 300 K and 700 K, which agrees well with those reported in the previous studies. The latter increases with the effective conduction length and the sp³ content. The present study provides fundamental information to develop the heat transfer model of the multi-layered structure of HDD under HAMR condition.