Ni纳米线的结构和性质研究

Study on the structures and properties of Ni nanowires

采用推广模拟退火算法(Generalized Simulated Annealing,GSA)和Sutton-Chen势,研究了初始构型为面心立方(fcc)结构的Ni纳米线,在沿径向压缩时的结构和性质.结果表明:径向压缩程度对Ni纳米线的结构有很大的影响.当Ni纳米线直径大于0.398nm时(初始直径为0.498nm),其结构由fcc结构变为类似fcc结构,但结合能变化很小,表明其结构之间几乎可以实现零能量转换,且稳定性基本不变;当Ni纳米线直径小于0.398nm时,其结构从无定形结构变为缺陷结构,结合能迅速上升,表明其结构稳定性降低;键角的分布也证明了以上结果的正确性.

Using the Generalized Simulated Annealing method with Sutton-Chen potential for the radial compression of fcc [111] Ni nanowire, the changes of atomic structure, binding energy, bond angle of Ni nanowires are studied. The results show that the compressed intensity greatly effects on the structures of Ni nanowires. When the diameter is over 0. 398 nm （normal value is 0. 498 nm）, and the structures of Ni nanowires are fcc-like and the binding energy changes very small, which indicates that the structures of Ni nanowire can transform each other nearly without changes of energy. When the diameter is below 0. 398 nm, the structures of Ni nanowires transform from amorphous to defect structure, and the binding energy greatly increases which indicates that the stability reduces. The evidences of the above results can be described by the discussion of bond angle.