金纳米线热稳定性的分子动力学模拟研究

A MOLECULAR DYNAMICS STUDY OF THERMAL STABILITY OF AU NANOWIRES

采用三维分子动力学模拟方法,以面心立方金属金为研究对象,基于Finnis-Sinclair型嵌入原子法(EAM)多体势,模拟研究了金纳米线的热稳定性。研究表明,金纳米线的熔化温度随着线径的减小而降低,熔化过程从表面开始,并逐渐向中心趋近,最后缩聚成球形团簇。纳米线在熔化过程中,温度也在逐渐升高,这不同于块体材料。Au纳米线的熔点比块体材料低很多,并且与纳米线的线径倒数成线性关系。

A three-dimensional molecular dynamics simulation method and Finnis-Sinclair embedded atom method （EAM） potential were utilized to study the thermal stability of an fcc Au nanowires, The results show that, the melting temperature of Au nanowires decrease with decreasing the diameter. The melting process starts from the surface, and then approaches to the center of the nanowires, and finally lead to the formation of the spherical clusters. It is shown that the temperature increases during the melting process, which is different from the melting of bulk Au. The melting point of Au nanowires were much lower than that of bulk Au. The melting points were linear with the reciprocal of the diameter of the nanowire.