Abstract
Crystalline dielectrics are better for thermal management in thin films due to higher thermal conductivity, κ than their amorphous counterparts. A powerful tool for investigating the mechanical, thermal, and structural properties of such dielectrics is Equilibrium Molecular Dynamics (EMD). However, EMD with the Green-Kubo (GK) approach, suffer from the selection of interatomic potentials. Conventional EMD/GK also becomes inadequate for bonded atoms with different masses as the Heat Current Autocorrelation Function (HCACF) decays differently compared to a monoatomic system. In this study instead of the conventional scheme to average the HCACF integral, a novel approach is proposed targeting only converged HCACF region eradicating substantial statistical error. This study aims to establish a modified EMD-GK approach to quantify the thermal conductivities of some important solid dielectrics including quartz, sapphire, and Wurtzite AlN. Applying the modified Systematic EMD/GK approach, Thermal conductivity in crystalline dielectrics with EMD-GK is successfully investigated. The uncertainty in the selection of empirical potentials is tackled by validating potentials against experimental thermal conductivity, atomic energy, atomic structure, and phonon properties.
