Easy growth of undoped and doped tungsten oxide nanowires with high purity and orientation

An economic method is presented to grow undoped/doped tungsten oxide nanowires with high purity and erect orientation, simply by heating a tungsten filament in a vacuum chamber with some room air leakage. Tungsten oxide nanowires were studied using scanning electron microscopy (SEM), energy dispersion x-ray spectroscopy (EDS) and transmission electron microscopy (TEM). Wires are found standing straight and clean on the filament, nm in diameter and up to a few tens of micrometres long. The composition along the wire is uniform for all elements including dopants.