Computer Simulation Study On The Mechanical And Magnetic Properties Of Quasi One Dimensional Nanomaterials

Since metal nanomaterials are introduced in the mid-1980s,the study of nanomaterials has become a hot topic.With the boost development of science and technology,the nanomaterials become the most promising new materials due to the unique force,electricity,heat,light and other characteristics.However,the experimental method encounters time and space constraints as the size of nanomaterials decreases.By contrast,computational simulations can make up for the deficiency of experimental methods.In the first part,we used the method of the first principle for the magnetic properties of silicene nanoribbons with bipartite lattice.We found that a potential spin order is afforded by the AB lattice,which was protected by the translation symmetry claiming the same states among the same sublattice point.On the other hand,this order was expressed respectively and concurrently in two subspaces,sp2-? and pz-?,and the spin orders in the two subspaces cancel each other,leading to no order expressed explicitly.Only by breaking this order degeneration in two subspaces,such as by introducing defect and edge decoration,make this order was expressed and controlled.Basing upon this,we implemented the FM ground states on both the ZSiNR and ASiNR by proper edge decoration.The present approach will enhance the understanding of the magnetism in 2D materials and will be helpful to design new type of nanomagnetism devices.In the second part,we researched the single axisymmetric stretch fracture characteristics of nanowires of copper and silver along[100]with molecular dynamics computer simulation.The results show that the tensile fracture position is not certain in the same condition,but there is a certain rule based on the many experimental results.We find this pattern and explain its mechanism from stress wave propagation and superposition.