立方铂纳米粒子的形状变化与熔化特性的分子动力学研究

Shape changes and melting characteristics of cubic Pt nanoparticle:A molecular dynamics study

采用分子动力学方法结合嵌入原子多体势,对立方铂纳米粒子的热稳定性进行了模拟研究.计算结果表明,立方纳米粒子在升温过程中首先转变为由{111}和{100}面所构成的十四面体,然后再转变为球形,最后熔化为液态.通过计算立方铂钠米粒子的统计半径,发现形状转变温度在1250K左右.尽管形状不同,立方纳米粒子和球形纳米粒子的熔点是相同的.

Molecular dynamics simulation is used to study the thermal stability of cubic platinum nanopartiele. The simulated results show that the cubic nanoparticle first transforms into the truncated cube enclosed by {111} and {100} facets, and then transforms to the spherical one. Finally, it melts into liquid state. The critical temperature of shape transformation is about 1250 K according to the calculation of statistical radius. Cubic and spherical nanoparticles have the same melting point in spite of their different shapes.