Atomic Scale Study Of Dynamic Behaviors On Supercooled Liquid Cu Clusters

Due to unique mechanical, electronic, optical and magnetic properties, materials with nano-structures have been paid a great deal of attention. Cu nanoclusters have attracted much interest from researchers.In the paper, relaxation and local structure changes of molten cupper cluster less than1000atoms have been investigated on atomic scale by molecular dynamics simulation within the framework of embedded atom method (EAM). By studying their structures, pair distribution functions, relative number of pairs and dynamic parameters including mean square displacement(MSD). incoherent intermediate scattering function, non-Gaussian parameter (NGP), the size effect and temperature effect on atomic structures and dynamic parameters are investigated as the clusters are quenched to different temperature.Structures on icosahedral geometries are the most favored structures for the small-sized quenched clusters. Icosahedron and FCC structures can be found for the clusters with middle-size during quenching, and it is presented for the motion differences among atoms on the surfaces and in the cluster interiors. As the atom number is reached over900, FCC is the most favored structures. For small-size clusters, diffusion motions of the atoms play a dominant role in local structure changes, but for bigger clusters, non-diffusion rearrangements play a dominant role in local structure changes. Different relaxation processes lead to different structures.