Metallic single-crystal CoSi nanowires via chemical vapor deposition of single-source precursor

We report the synthesis, structural characterization, and electrical transport properties of free-standing single-crystal CoSi nanowires synthesized via a single-source precursor route. Nanowires with diameters of 10-150 nm and lengths of greater than 10 mu m were synthesized through the chemical vapor deposition of Co(SiCl3)(CO)(4) onto silicon substrates that were covered with 1-2 nm thick SiO2. Transmission electron microscopy confirms the single-crystal structure of the cubic CoSi. X-ray absorption and emission spectroscopy confirm the chemical identity and show the expected metallic nature of CoSi, which is further verified by room-temperature and low-temperature electrical transport measurements of nanowire devices. The average resistivity of CoSi nanowires is found to be about 510 mu Omega cm. Our general and rational nanowire synthesis approach will lead to a broad class of silicide nanowires, including those metallic materials that serve as high-quality building blocks for nanoelectronics and magnetic semiconducting Fe1-xCoxSi suitable for silicon-based spintronics.