碳纳米管表面金纳米线的结构与热稳定性分析

ANALYSIS ON STRUCTURE AND THERMAL STABILITY OF GOLD NANOWIRE COVERED ON THE SURFACE OF CARBON NANOTUBE

采用分子动力学方法研究了覆盖在碳纳米管表面的金原子所形成的结构及其热稳定性.研究结果表明,金原子在碳纳米管表面能形成多样而稳定的结构:当金原子覆盖密度低于15.91时,形成金纳米颗粒;当原子覆盖密度为15.91～104.98时,形成一系列的壳层结构;而当原子覆盖密度大于104.98时,则呈现晶体金的面心立方结构.在对有碳纳米管支撑的金纳米壳层结构的热稳定性进行研究后,发现其熔点高于金纳米颗粒的熔点而且低于金纳米线的熔点.

In this paper,we study the structure and the thermal stability of gold atoms covered on the surface of carbon nanotubes by molecular dynamics simulations.It is shown that,diversiform stable structures can form on the surfaces of carbon nanotubes： when the density of gold atoms covered on the surfaces of carbon nanotubes is less than 15.91,gold atoms would form gold nanoparticles,when the density is between 15.91 and 104.98,gold atoms would form a series of cylindrical and helical shell structures,when the density is greater than 104.98,gold atoms would have the face centered cubic structure like the crystalline bulk gold.Further more,we have also studied the thermal stability of the helical shell nanowires with the carbon nanotubes’ support.The results show that the melting point of the helical shell nanowires with the carbon nanotubes’ support is lower than the gold nanowires formed in a free space,but higher than that of the gold nanoparticles.