超晶格薄膜热传导的分子动力学模拟

采用非平衡态分子动力学方法模拟了超晶格薄膜的热传导性能，并对其主要影响因素作了分析．模拟结果显示，周期长度固定的超晶格薄膜，界面热阻在总热阻中的比例和导热系数同周期数无关；当超晶格薄膜的膜厚不变时，导热系数将随着周期长度的增大而增大，但由于超晶格薄膜晶格常数的不匹配，使其内部发生明显的几何形变，这种变化关系也愈加复杂，同时周期长度的增加，平均界面热阻也随着增大，揭示了界面热阻不仅取决于界面层的物理条件，而且也与构成的介质内部形变有着重要关系．

Molecular dynamics simulation of superlattice thermal conductivities

The thermal properties of superlattices are simulated by non-equilibrium molecular dynamics(NEMD) method, and various factors that affect the heat transfer in superlattice structures are analyzed based on the simulation results. It is found that the thermal conductivity and the proportion of interface thermal resistance to total thermal resistance have no relation with the number of periods for the superlattice structure with a fixed period length. However, when the total width of the thin film is fixed, the thermal conductivity will increase with the period length and the interface distortion can be observed due to the lattice constant mismatch. Simultaneously the average interface thermal resistance will go up with period length, which demonstrates the interface thermal resistance not only depends on the physical conditions of interfaces, but also depends on the geometric distortion of interfaces.