Effects of crystal orientations of the facets on the structural stability of metallic Ni nanorods

By means of molecular dynamics simulations, the structural stability of metallic nickel nanorods is investigated under the condition of room temperature. The numerical results show that two parameters are closely related to the stability of nickel nanorod, one of them is its diameter whereas the other is the sort of facets wrapping the nanorod or the axial orientation of the nanorod. The nanorod is stable when its diameter is larger than about 2.8 nm and unstable when the diameter is smaller than 1.2 nm. When the diameter is between 1.2 and 2.8 nm, the instability behavior of the nanorod changes with its axial orientation, and is found to be determined by the sorts of facets forming the surfaces of nanorod. For the surface, the larger the fraction of {111} facets, the more stable is the nanorod. The nanorod wrapped by {110} or {100} facets is the least stable.