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Abstract This work introduces a theoretical formulation and develops numerical methods for finite element implementation of the formulation so as to extend the concurrent atomistic-continuum (CAC) method for modeling and simulation of finite-temperature materials processes. With significantly reduced degrees of freedom, the CAC simulations are shown to reproduce the results of atomically resolved molecular dynamics simulations for phonon density of states, velocity distributions, equilibrium temperature field of the underlying atomistic model, and also the density, type, and structure of dislocations formed during the kinetic processes of heteroepitaxy. This work also demonstrates the need of a mesoscale tool for simulations of heteroepitaxy, as well as the unique advantage of the CAC method in simulation of the defect formation processes during heteroepitaxy. 

We present a molecular dynamics study of the thermal transport properties of PbTe/PbSe (111) and PbTe/PbSe (100) interfaces at room temperature. The PbTe/PbSe heterostructures are obtained through simulations of the kinetic processes of direct bonding of PbTe and PbSe crystals. The atomic-scale dislocation core structures and the misfit dislocation networks in the heterostructures obtained in the simulations are found to closely match experimental data. Two types of heat transfer experiments are then simulated: a heat-sink heat-source experiment and an ultrashort heat pulse experiment. Thermal boundary resistance is calculated for three distinct interface types: coherent, semi-coherent, and semi-coherent with pinned dislocations. Both types of simulations consistently capture the significant role of the misfit dislocations on thermal resistance. The effect of the mobility of dislocations on thermal resistance is demonstrated for the first time through comparing the thermal boundary resistance of interfaces containing pinned dislocations and with those containing unpinned dislocations. In addition, the thermal boundary resistance is found to strongly depend on the length of the specimen and the area of the interface.