中文摘要：

运用分子动力学结合退火方法，模拟研究了所含原子数介于400～20000之间的自由及支撑Co团簇的熔化行为．模拟中团簇Co原子间相互作用采用半经验的Gupta多体相互作用势．讨论了不同衬底势（Lennard-Jones势与Morse势）对支撑团簇熔化行为的影响．结果表明：对于给定原子数目的支撑Co团簇，在衬底势强度相同时，两种衬底势下对支撑团簇熔点及预熔化区间给出了一致的描述；随衬底势强度增加，支撑团簇熔点升高，且两种衬底势所描述的支撑Co团簇也类同于自由Co团簇都表现出较好的熔点与尺寸依赖的线性关系．

英文摘要：

The molecular dynamics simulation combined with the simulated annealing method are used to study the melting behaviors of free cobalt clusters and two kinds of supported cobalt clusters with clus- ter size ranging from 400 to 20000 atoms. Gupta potential is used for the cobalt - cobalt interactions in Co clusters. Influences on the melting properties are discussed with two kinds of supported potentials： the Lennard-Jones potential and the Morse potential. Our results reveal that with the same number of cobalt atoms and the same cobalt-substrate interation stength, the melting points and pre-melting intervals of the two kinds of supported Co clusters are all in reasonable agreement with each other. With increasing the depth of supported potential, the melting points increase for the supported cluster. Similar to the case of free clusters, the linear relation between the melting point and the inverse of cluster＇s size cube root is also found for the two kinds of supported clusters.