Al_n(n﹤10000)团簇熔化行为的分子动力学模拟  

Molecular dynamical simulations of melting properties of Al_n(n < 10000) clusters

作　　者：伊力亚尔.海米提 李春丽[1] 方萌[1] 段海明[1] 

机构地区：[1]新疆大学物理科学与技术学院,乌鲁木齐830046

出　　处：《原子与分子物理学报》2015年第1期71-78,共8页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(10864005;11164029);新疆维吾尔自治区自然科学基金(2011211A008)

摘　　要：采用半经验的Gupta原子间多体势,运用分子动力学模拟结合退火技术,由不同初始结构（密堆积满壳层Ih、Oh结构及退火结构）出发,研究了尺寸在10000个原子之内的Al团簇的熔化行为.结果表明：在所研究团簇尺寸范围内,Ih结构均具有高的动力学稳定性;Oh结构的动力学稳定性与团簇尺寸密切相关：尺寸较小（1000个原子以内）时不稳定（熔化前会发生向类Ih结构的转变）,在中间尺寸（1000~2000原子间）时动力学稳定性发生转变,尺寸较大（2000原子以上）时显示出完整的动力学稳定性;从不同初始结构出发所得相同尺寸团簇熔点基本相同;在200原子以上时,团簇熔点随尺寸变大而升高且体现出近似的线性关系.Applying the semi - empirical multi - body Gupta potential, combining the molecular Oynamm slmuation method with annealing technique, we have studied the melting behaviors of Aln （n 〈 10000 ）clusters for three kinds of initial structures ： the icosahedron, the truncated octahedron and the structures obtained by annealing technique. Our results showed that：the icosahedral structures have the best stability. Stability of octahedral structures is strongly related with the cluster sizes：clusters in small sizes （less than 1000 atoms） are very unstable （ turned into Ih structure before melting）. For medium sizes （between 1000 and 2000 atoms） ,there is a change in the dynamic stability. Clusters which have big sizes （more than 2000 atoms） are completely stable. Differences in initial structures have no effect on the melting point of aluminum clusters. An approximate linear relationship can be seen from the cluster size dependence of melting point of aluminum clusters and the melting point of cluster increases with increasing cluster size.

关 键 词：GUPTA势 团簇 分子动力学 熔化 

分 类 号：O469[理学—凝聚态物理] O561.1[理学—电子物理学]