银纳米线熔化过程的分子动力学模拟

A Molecular Dynamics Study on the Melting of Silver Nanowires

采用分子动力学方法和量子修正的Sutton-Chen(QSC)多体势研究了不同尺寸的银纳米线的熔化动力学过程.模拟结果表明:银纳米线的熔点要比银的体材料的熔点低得多,并且与纳米线的直径的倒数成线性关系,当纳米线的直径越大时,其熔点越高,表现出了明显的尺寸效应.银纳米线的熔化过程首先从表面开始,并逐步向内部发展,直至核心区域.当温度高于熔点时,银纳米线逐渐熔化、断裂,最后形成球形团簇.

The melting processes of silver nanowires with different sizes were studied using molecular dynamics simulations with the quantum Sutten-Chen many-body force field. The present calculations indicated that the melting temperatures of silver nanowires were much lower than that of silver bulk,showing a strong dependence on the size of the nanowires. The melting temperatures were linear with the reciprocal of the diameter of the nanowire. The melting process first occured at the edges of the nanowires, and then spreaded to the core region. When nanowires were heated up above the melting temperatures, they would melt gradually,then break, and finally lead to the formation of the spherical clusters.