Fragmentation of nanowires driven by Rayleigh instability

Rayleigh instability of copper nanowires has been experimentally demonstrated. After annealing 30-50-nm-diam wires at temperatures between 400 and 600degreesC, different stages of the fragmentation process are observed by scanning electron microscopy. At 400degreesC, the wires start to fragment, forming shorter sections at 500degreesC, and finally decaying into a chain of nanospheres at 600degreesC. Average diameter and spacing of the spheres are in agreement with theoretical predictions. The Rayleigh instability applied to nanowires provides a structuring technique producing long chains of nanospheres, which should find interesting applications, for instance, by guiding light below the diffraction limit via coherent coupling of surface-plasmon polaritons. (C) 2004 American Institute of Physics.