NEMD方法:预测修饰型(6,6)单壁碳化硅纳米管的热导率

NEMD:Prediction of the thermal conductivity of the modified(6,6)single-wall silicon carbide nanotubes

采用了非平衡分子动力学方法,分别计算了相同管径下N、P修饰碳化硅纳米管的热导率.得到了热导率随掺杂原子数占总原子数的百分比变化的曲线,进而根据这些曲线,讨论掺杂原子数占总原子数的百分比对碳化硅纳米管热导率的影响,以及掺杂原子不同导致的热导率差异.研究结果表明,由于掺杂存在于晶格结构中,声子平均自由程的大小将会受到不可忽视的影响.在相同条件下,掺杂原子数占总原子数的百分比越大,声子与杂质之间的散射概率也随之增大,热阻变大,碳化硅纳米管热导率越小.P修饰的(6,6)单壁碳化硅纳米管的热导率下降趋势明显高于N修饰的(6,6)单壁碳化硅纳米管.

Using non-equilibrium molecular dynamics method to calculate the thermal conductivity of silicon carbide nanotubes of the same pipe diameter with N/P modified.Get the curve of thermalconductivity changing with doping concentrations,and discussing the influences of doping concentration in silicon carbide nanotubes,and the differences in thermal conductivity with different kinds of atoms.Due to doping exists in lattice structures according the research result,the size of phonon’s average free path will be affected and it cannot be ignored.In the same conditions,the more doping concentration is,the bigger the scattering probability between phonons and impurity will increase subsequently,the thermal resistance will be smaller,the thermalconductivity of silicon carbide nanotubes will be micrified.P atoms modified(6,6)single wall thermal conductivity of silicon carbide nanotubes decline significantly higher than N atoms modified(6,6)single wall thermal conductivity of silicon carbide nanotubes