Simulation and prediction on phonon thermal conductivity of Al/Cu interface

Abstract

Based on the non-equilibrium molecular dynamics (NEMD) method, phonon thermal conductivity of Al/Cu interfaces is systematically studied by considering the temperature dependence and size effect of thickness under different temperatures, for which an approximate mathematical model is also proposed. In this model, phonon thermal conductivity can be described by the thermal conductivities of Al and Cu thin materials according to the electrical thermal transport and the free electron approximation theories. Meanwhile, the thermal conductivities of each thin films can be described using the thermal conductivities of each bulk materials due to the Wiedemann-Franz Law under the thin thickness (less than the mean free path) and below the recrystallization temperature. The results show that the contribution of Al and Cu is inversely proportional to the interface thermal conductivity. This investigation based on the thermal and electronic conductivity of bulk materials, is helpful for understanding the interface heat transfer mechanism of interface structures, which also implies a potential method for the analysis of thermal performance of interfaces and design of interface structures.