Metal Ag Nano Rod And Nano Thermal Stability Of Atomic Clusters Structure Simulation Studies

Due to the excellent properties of nanometer material, such as surface effect, quantum sizeeffect, small size effect and macro tunnel effect, which is very different from macro blockmaterial, more and more research workers begin to pay great attention on nanotechnology,especially on nanoclusters and nonrods.Used the molecular dynamics simulation method, we have studied with Ag nanorods andnanoclusters, simulated the evolution processes of nanorods and cubic nonoclusters’ relaxtion atvarious temperatures and lengths, and analyses the Ag nanorods’ steady structure, averagepotential energy changes and the evolution process of Ag nanorods’ structure.The results show that there is a critical breaking temperature (Ta) which is decreasing withincreasing Ag naorod’s length. The Ag nanorod is melted to one highly dis-ordered sphericalcluster when the temperature is between melting point and the critical breaking temperature (Ta)but melted to two spherical clusters when the temperature is above the critical breakingtemperature (Ta).The inner regimes of the structure evolution processes at various temperaturesare presented. There is a critical instability temperature of the cubic nanoclusters of249Ag atoms.When the temperature is below the critical instability temperature, the Ag nanoclusters keep itsnearly cubic structure. When the temperature is above the critical instability temperature, theatoms of Ag nanocluster will rearrange under short time annealing, and form relatively stable facecentered polyhedron structure unchanged obviously until melted.When the temperature is abovethe melting point, the structure is melted and forms a highly dis-ordered spherical cluster.Themelting points of Ag nanoclusters and nanorods are below the melting point of block, and thereare negative heat capacities phenomenons happen near the melting point.