Size effects on the melting of nickel nanowires: a molecular dynamics study

The melting process of nickel nanowires are simulated by using molecular dynamics with the quantum Sutten-Chen many-body force field. The wires studied were approximately cylindrical in cross-section and periodic boundary conditions were applied along their length; the atoms were arranged initially in a face-centred cubic structure with the [0 0 1] direction parallel to the long axis of the wire. The size effects of the nanowires on the melting temperatures are investigated. We find that for the nanoscale regime, the melting temperatures of Ni nanowires are much lower than that of the bulk and are linear with the reciprocal of the diameter of the nanowire. When a nanowire is heated up above the melting temperature, the neck of the nanowire begins to arise and the diameter of neck decreases rapidly with the equilibrated running time. Finally, the breaking of nanowire arises, which leads to the formation of the spherical clusters. (C) 2004 Elsevier B.V. All rights reserved.