TiO_2/ZnO纳米薄膜界面热导率的分子动力学模拟

Molecular dynamics simulation of thermal conductivity for the TiO_2/ZnO nano-film interface

采用平衡分子动力学方法及Buckingham势研究了金红石型TiO2薄膜与闪锌矿型ZnO薄膜构筑的纳米薄膜界面沿晶面[0001](z轴方向)的热导率.通过优化分子模拟初始条件中的截断半径rc和时间步后,计算并分析了平衡温度、薄膜厚度、薄膜截面大小对热导率的影响.研究表明,薄膜热导率受薄膜温度和厚度的影响很大,当温度由300K升高600K时,薄膜的热导率逐渐减小;当薄膜厚度由1.8nm增大到5nm时,热导率会逐渐增大;并在此基础上对更大厚度范围内TiO2/ZnO界面热导率可能变化性态进行了探讨.

In the paper,the equilibrium molecular dynamics and Buckingham potential function are used to investigate the thermal conductivity of TiO2/ZnO nano-film interface along to [0001]（z-axis）.The effects of the equilibrium temperature,the thickness and the cross section of the nano-film interface on the thermal conductivity of TiO2/ZnO are investigated by optimizing the cut-off radius（rc）and the time step for initial condition of molecular dynamics.The results indicate that the thermal conductivity of TiO2/ZnO nano-film interface decreases with temperature increasing from 300 K to 600 K,and increases with film thickness increasing from 1.8 to 5 nm.Finally,the relationship between the thermal conductivity and the thickness of TiO2/ZnO nano-film interface is discussed.