Laser-driven growth of oxide micro- and nanostructures

Vanadium pentoxide films have been grown in air in the field of infrared laser light (CW CO2 and YAG) on the surface of a metallic vanadium sheet. In the irradiated area, we obtain a tubular rectangular form of microtubes and nanowires of characteristic measurements from 0.02x0.03x0.1 to 2x2x10 cubic microns. The tubes are empty, having a huge free surface (more than 10,000 square meters per gram). The size of the tubes depends on the local temperature gradients formed under the influence of laser light at the metal-oxide interferences. In some cases, the formation of a dense network of nanowires is also observed. In peripherical zones far from the laser spot center, we observe the growth of mosaic-like structures with random orientations. In situ temperature measurements reveal the role of vertical temperature gradients in different sizes of nanostructures