Molecular Dynamics Simulation For Mechanical，Thermal Transport Properties Of Silicene Nanostructures

In recent years，a type of nanomaterials, which are very similar to thematerial of graphene, called as silicene have been emerged in the world. If thistype of material exhibits considerably superior mechanical, thermal andelectrical properties in comparison with pure graphene, it will definitely leadthe thermoelectric materials researches up to a new stage. In this work, twomain research projects, i.e., the mechanical properties and thermoelectricproperties of the silicene nanostructures are investigated. First, the moleculardynamics simulations are employed to investigate the mechanical properties,combined with uniaxial tensile test and different empirical potentials, theYoung’s moduli of both armchair direction silicene and zigzag directionsilicene nanoribbons are calculated, and associated comparative analyses aregiven. Then, how the Young’s modulis of the two kinds of silicenenanoribbons affected by their different widths are investigated by using theEDIP potential functions. In addition, the changes of bond length and bondangle, the phenomena of fracture and sliding in silicene nanoribbons areobserved and analyzed by means of the numerical tensional test, the relatedvariation rule and mechanism are obtained accordingly. Secondly, in the fieldof nonequilibrium molecular dynamics, the thermal conductivities of thearmchair direction silicene nanorbbons and zigzag direction silicenenanoribbons are calculated by using associated thermal conductivity foumuli.The thermal conductivities affected by different widths and chiralities areinvestigated and the variation mechanisms are also summarized and presented.Finally, the phonon density of States（PDOS） of silicene nanorbbons arecalculated when heat conduction occurs, and how thermal conductivities of thesilicene nanorbbons influenced by their width is analyzed by means of thePDOS simulation curves.