Abstract: Heat conduction in carbon nanotubes was simulated by nonequilibrium molecular dynamics method with reactive bond order (REBO) potential.Combined with phonon spectrum analysis based on the first principles，thermal effects of three types of point defects such as doping，absorption and vacancy were analyzed.Influences of major factors including ambient temperature，length and radius of carbon nanotube were studied.Thermal conductivities of carbon nanotubes without defects were also calculated for comparison.Simulation results show that a sharp jump in the temperature profile occurs at defect positions.Thermal conductivity of nanotubes decreases significantly due to point defects.The defect type plays a more important role on the thermal conductivity than the length or the radius of carbon nanotubes.The relative influences of three types of defect on the thermal conductivity are in the order of vacancy>doping> adsorption.

Key words: carbon nanotube, thermal conductivity, defect, molecular dynamic, first-principles

摘要： 采用非平衡分子动力学方法，选用反应经验键序势能，模拟了分别含有掺杂、吸附和空位点缺陷的碳纳米管的导热，并开展了基于第一性原理的声子谱分析；研究了碳管长度、管径、手性以及环境温度等因素的影响。缺陷效应分析表明：与完整无缺陷碳纳米管相比，掺杂、吸附和空位均会导致碳管热导率显著下降，以及碳管轴向温度分布在缺陷处产生非线性的间断性跳跃；缺陷类型对碳管热导率的影响最大，管径次之，管长影响相对最小；而空位、掺杂和吸附对碳管热导率的影响力依次是减小的。

关键词: 碳纳米管, 热导率, 缺陷, 分子动力学, 第一性原理