Molecular Dynamics Simulation Of Structure,Deformation And The Related Mechanical Properties Of The Silicon Clusters

Cluster is the relatively stable aggregates composed by several to thousands of atoms, molecules or irons. It has caught much attention because of its unique properties. The study of structure is the base of the study of all the other characteristics of clusters. In the research of the bulk, people have made out a lot of of bulk materials with non-ground state structure. These materials are often more excellent than the traditional materials. For clusters, people are currently pay more attation on the ground state structures. However, in fact, there are many non-ground state structure,some of which are very stable. Silicon material is the cornerstone of the electronics industry, so the study of the state structures of silicon clusters has important scientific significance and application value.In this paper, we use the method of molecular dynamics and potential function of Stillinger-Weber for different models and different temperature conditions to obtain the steady-state structures of silicon clusters Sin (n = 4-35). We found the formed steady-state structures of clusters are very sensitive to the initial structure and temperature. The obtained silicon clusters have different geometries for different initial structures and temperature. In general, the formed clusters structure is more regular and better symmetry while the number of atoms is few, and only distributes in the cluster surface. The clusters with large number atoms are pieced by the clusters with small number atoms, and there is internal atoms in this large clusters. The atoms on the surface of silicon clusters often form space pentagon structure. The article also use Tersoff potential function and the method of silicon atoms replacing of carbon atom in the fullerene to obtain the Si6 0 structure..Furthermore , with the invention and development of nano-mechanics, the study of the mechanical behavior of various mechanical components becomes very urgent.Clusters are one of the most important part candidates of nano-mechanical systems.In this article, we also carry out the molecular dynamics simulation of tension and compression to the stable structure of Si1 3. The reslults show that strength and strain is linear in the initial stage of tension and compression. The force is greater when the temperature is higher in the tension. On the contrary, the force is smaller when the temperature is higher in the compression. The force of tension is significantly higher than the force of compression for the same strain. When the tensile strain reaches the limit load, the force of tension suddenly becomes very small, because clusters structures change. Followed by stretching, the force and strain have shown the same linear relationship in the initial stages.