Controlled fabrication of 1-2 nm nanogaps by electromigration in gold and gold-palladium nanowires

The authors report the electrical characterization of gold and gold-palladium nanowires failed by electromigration. Nanogaps 1-2 nm in size are reliably made from metal nanowires by controlling the electromigration failure process, opening up the possibility of using these metal nanowires with nanogaps for molecular conduction studies and large-scale molecular junction device fabrication. Nanogaps are formed by applying a voltage sweep to the wires at a ramp rate of 4 mV/s. The interplay between Joule heating and electromigration means that reliable nanogaps can be formed without the need of a feedback circuit, rendering the technique relatively simple to implement.(c) 2007 American Institute of Physics.