尺寸效应对Al纳米线凝固行为的影响

结合EAM镶嵌原子作用势, 通过经典的分子动力学模拟研究了不同截面尺寸Al纳米线在两种冷却速率下的凝固行为, 并采用键对分析技术探讨了相变过程中原子团簇的演化情况. 结果表明:Al纳米线的最终结构不仅与冷却速率有关, 还呈现出明显的尺寸效应. 在较快的冷却速率下, 五种截面尺寸的Al纳米线均得到了多壳螺旋结构; 而当冷却速率降低以后, 除了N₃纳米线发生了断裂以外, 其余纳米线的结构随着截面尺寸的增加, 逐渐从多壳螺旋结构经由类-六边形多壳结构最终过渡到稳定的晶态结构.

Size effect on the freezing behavior of aluminum nanowires

The freezing behaviors of Al nanowires with different section sizes and cooling rates are studied by using the classic molecular dynamics simulation via embedded atom potentials. In order to invesligate the evolution of the local clusters in the transformation of Al nanowires, the pair analysis technique is employed. The simulation results indicate that the final structure of Al nanowires is strongly affected not only by cooling rate, but also by the size effect during solidification from liquid. At a rapid cooling rate, the final structures are all helical multi-shelled structures. However, at a slower cooling rate, the structure changes from helical multi-shelled to crystalline via near-hexagonal shell structure with the increase of section size except that the thinnest Al nanowires break down.