物理化学学报 >> 2003, Vol. 19 >> Issue (01): 35-39.doi: 10.3866/PKU.WHXB20030109

研究论文 上一篇    下一篇

中介尺度Au纳米团簇熔化的分子动力学模拟

张妍宁;王丽;边秀房   

  1. 山东大学材料液态结构及其遗传性教育部重点实验室,济南 250061
  • 收稿日期:2002-05-16 修回日期:2002-07-05 发布日期:2003-01-15
  • 通讯作者: 张妍宁 E-mail:zhangyanning_421@hotmail.com

Melting of Au Nanoclusters by Molecular Dynamics Simulation

Zhang Yan-Ning;Wang Li;Bian Xiu-Fang   

  1. The Key Laboratory of Liquid Structure and Heredity of Materials,Ministry of Education, Shandong University, Jinan 250061
  • Received:2002-05-16 Revised:2002-07-05 Published:2003-01-15
  • Contact: Zhang Yan-Ning E-mail:zhangyanning_421@hotmail.com

摘要: 采用分子动力学模拟技术,研究了原子个数为16~8628的 Au纳米团簇的熔化过程.采用 Johnson的EAM (embedded atom method) 模型,模拟结果表明,金属纳米团簇存在一中介尺度区域.对Au纳米团簇而言,当原子个数N >456时,团簇的热力学性质与团簇尺寸呈线性关系,熔化首先从表面开始,逐步向中心区域推进,且满足Tmb-Tmc(N)=aN(-1/3)的关系.另外,计算了中介区域的团簇的尺寸、熔化温度、表面能、熵、焓等热力学量以及均方根位移(RMSD)等动力学量,为研究纳米团簇提供定量数据.

关键词: 分子动力学模拟, Au纳米团簇, 熔化过程

Abstract: We present a detailed molecular dynamics study of the melting of Au nanoclusters with up to 8628 atoms within the framework of the embedded atom method(EAM). The simulation indicates that there exists a mesoscale nanocrystal regime in metal nanoclusters. The predicted thermodynamics properties for Au nanoclusters above 456 atoms show a linear dependence on the cluster size, whereas the melting begins from the surface of the clusters with a melting point at Tmb-Tmc(N)=aN(-1/3). In addition, the cluster size, surface energy as well as the average root-mean-square displacement (RMSD) of the clusters in the intermediate regime have been investigated.

Key words: Molecular dynamics simulation, Au nanoclusters, Melting process