Synthesis of single-crystalline tungsten nanowires by nickel-catalyzed vapor-phase method at 850°C

Single-crystalline tungsten nanowires have been synthesized by nickel-catalyzed vapor-phase methods at a temperature of 850 degrees C. The synthesis temperature is significantly below the eutectic temperature of Ni-W binary system (1495 degrees C) which indicates that the growth of the nickel-catalyzed tungsten nanowires should be controlled by the vapor-solid-solid mechanism. Moreover, calculation results show that the W atoms for the nanowire growth should be transported by the surface diffusion along the hemispherical catalyst particle shell to the interface between catalyst particle and the growing W nanowires. Our study, for the first time, demonstrates that the powerful metalcatalyzed methods are feasible to process metallic nanowires. (c) 2007 Elsevier B.V. All rights reserved.