Molecular-Dynamics Simulation Study On The Rearrangement Collisions Processes Between Metal Clusters

The research on atom cluster is about the relationship among the microscopic structure, physical and chemical characters, size on the evolution to macroscopic matters, and the interaction with external environment of atoms and electrons in cluster. The research on cluster involves the interaction of several stems of science. The cluster typically is regarded as the thing between microscopic matters such as atoms and molecules and macroscopic matters. It is a transitional status, and can help us to understand the qualities and principles of the condensed processes of massive matters, so dose to understand the characteristics of nanomaterials. Metal nanomaterials have very important applying value and have received widespread attention. It's important for us to study the collision rearrangement process of metal clusters. It can help us to understand the deposition of clusters and how metal films and bulk materials coming to being.In this paper, collision processes between two gold clusters or gold-silver clusters under different collision energy are investigated using molecular dynamics in combination with embedded atom potentials. We study the principle of collision rearrangement of clusters, and what effects has collision oriental conditions done to the rearrangement collision of clusters.The initial gold and silver clusters investigated are incised from FCC crystal to a certainty radius, which radiuses are 1.0,,,,,2.0 and (unit is crystal constant) and the atoms corresponding are 16, 44, 68, 80, 104, 140, 152. Clusters are annealed before simulating collision processes. Collision between two equal gold clusters , two not equal gold clusters and gold-silver clusters are investigated. The collision energy per atom of projectile cluster is varied from to . The results included in our simulation mainly are: (1) For the same target and projectile clusters, the temperature of some new clusters is not merely increasing monotonously. For the lower collision energy, the temperature of new cluster after collision is not merely increasing monotonously with the increase of atoms of projectile cluster, because clusters maybe relax to stable or metastable structures under different collision conditions.(2) Temperature of gold-silver alloy cluster is higher than that of gold-gold cluster after rearrangement collision under the same collision condition, because there are heats of formation of alloy and the atoms of new cluster have lower potential.(3) For the collisions of gold clusters and silver clusters, adding silver atoms will increase the disorder of alloy clusters, thus cause the alloy clusters far away from forming form the quasi-crystal icosahedron, which has lower energy status.(4) It will do great effect to the rearrangement collision process and the characters of cluster after rearrangement when projectile energy is different. Higher collision energy may be more helpful to form the quasi-crystal icosahedron, which has lower energy status, when cooling to 300K after rearrangement collision of two gold clusters.The simulation results above are still no seen reported in domestic journals. Though they still need to be illustrated, they have some certain directive purport and reference worth on preparing stable nanomaterial in lab. Moreover, they can supervise further simulation calculation from these results, and will be helpful to go deep into understanding the characters of clusters.