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 600 ° C , different stages of the fragmentation process are observed by scanning electron microscopy. At 400 ° C , the wires start to fragment, forming shorter sections at 500 ° C , and finally decaying into a chain of nanospheres at 600 ° C . 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.