Optimisation study of the synthesis of vanadium oxide nanostructures using pulsed laser deposition

Abstract

Fast imaging plasma plume study have been carried out on vanadium-oxygen plasma generated using 248 nm, 25 ns pulses from an excimer KrF laser under oxygen atmosphere. The plume expansion dynamics of an ablated VO(sub2) target was investigated using a fast-imaging technique. The free expansion, splitting, sharpening and stopping of the plume were observed during these oxygen pressures, 0.01, 0.05, 0.10 and 0.20 mbar. The influence of the plume dynamics study on the properties of the obtained vanadium oxide thin films were examined using X-Ray Diffraction method. A vanadium dioxide phases were deposited at 0.05 mbar oxygen pressure for target-substrate distance of 40 mm and 50 mm. Mixed phases of vanadium oxide were deposited at 0.01, 0.10 and 0.20 mbar oxygen pressure for target-substrate distance of 40 mm. Transition temperatures of around 60.9(supo)C have been measured from sample deposited at 0.05 mbar oxygen pressure for target-substrate distance of 50 mm. We observe mixed nanostructures for thin film prepared at 0.05 mbar for target-substrate distance of 40 mm, while the thin film prepared at 0.05 mbar for target-substrate of 50 mm shows an uniform nanostructure film.