Preparation of VO2 nanowires and their electric characterization

Large-scale VO2 nanowires have been synthesized by two-step method. First, we have been obtained (NH4)(0.5)V2O5 nanowire precursors by hydrothermal treatment of ammonium metavanadate solution at 170 degreesC. Secondly, the precursors have been sealed in quartz tube in vacuum and annealed to form VO2 nanowires at 570 degreesC. Scanning electron microscope and transmission electron microscope analysis show, that the nanowires have self-assembling nanostructure with the diameter of about 80-200 nm, length up to125 mum. Electrical transport, measurements show that it is semiconductor with conduction activate energy of 0.128 eV. A metal semiconductor transition can be observed around 341 K. (C) 2004 Elsevier Ltd. All rights reserved.