Molecular Dynamics Simulations of SiSe2 Nanowires

Abstract

AbstractStructural and mechanical behavior of SiSe2 nanowires is investigated with the moleculardynamics (MD) method. Nanowires contain finite number of non-intersecting chains of edgesharing Si(Sel/2)4 tetrahedra. The simulations are based on an effective interatomic potential containing both 2- and 3-body interactions. It is found that the nanowires remain highly crystalline and stay in the elastic deformation regime up to a critical strain. Under large uniaxial strain, fracture of the nanowires is initiated by broken bonds in one of the chains at the outermost layer. This induces cross-linking among the neighboring chains, which leads to the presence of cornersharing tetrahedra and local amorphization. Local amorphization propagates across nanowires while multiple cracks start at the boundaries of the amorphous region. The dynamics of amorphization and fracture are discussed.