Quasi-aligned MoO3 nanotubes grown on Ta substrate

Using infrared irradiation to heat a Mo foil in a moderate vacuum (5 Torr), quasi-aligned MoO3 nanotubes, about 5–8 μm long, were prepared on a Ta substrate. Most of the nanostructures show polygonal morphology with a hollow core in cross-sections. The width of nanotubes range from 50 to 300 nm, and the hollow core are about 20–150 nm in diameters. The nanotubes possess orthorhombic single-crystal structure and have preferentially grown along the [1 0 0] direction. Stacking faults normally form on the (0 2 0) planes, resulting from the layered structures.