Facile synthesis of single crystalline metallic RuO₂ nanowires and electromigration-induced transport properties

We report a simple strategy to synthesize highly crystalline ruthenium dioxide (RuO₂) nanowires by atmospheric pressure chemical vapor deposition in supercooled liquid nanodroplets without the use of catalyst particles. The nanowires are single crystals with no discernible amorphous layers or defects. The pretreatment of the substrate is found to be effective for the position controlled growth of the nanowires as small as 10 nm. The RuO₂ nanowires have extremely low electrical resistivity of 62.5 ± 8.8 μΩ•cm and uniform electrical materials characteristics, regardless of size. By passing high current (>10⁷ A/cm²) through the nanowires, very small nanogaps of less than 5 nm are produced, which can be explained by a heuristic model, in which electromigrative and surface diffusional effects are included.