Synthesis And Preparation Of Tungsten And Molybdenum Doped VO₂ Powders And Thin Films For Performance Research

VO2(M) is a typical phase transition transition metal oxide, having the metal-semiconductor phase transition characteristics. During the transition, it occurs with mutations in the electrical optical properties, which have made VO2(M) be fully applied in many area, Such as Smart windows, Infrared pulse laser protection, Photoelectric switch and Optical storage materials etc.In this paper, we use the hydrothermal method on ultra-fast and low temperature conditions to prepare doped vanadium dioxide VO2 Powders, and also prepared vanadium dioxide VO2 powders having different microscopic morphology. And we also use the organic Sol-Gel to prepare the doped vanadium dioxide VO2 Film.The article drew the following conclusions:(1) Under hydrothermal conditions, the choice of citric acid monohydrate as a reducing agent, and the reaction temperature is 180 ℃, reaction time is 2h, with ultra-fast low temperature conditions for a successful preparation B phase doped vanadium dioxide VO2 powder.(2) Under the nitrogen atmosphere, at the annealing temperature of 500 ~ 600 ℃, and the annealing time is 3 ~ 9h, on these annealed conditions, B phase vanadium dioxide VO2 powder can be converted into M phase vanadium dioxide VO2 powder.(3) Also in the hydrothermal method, the selection of n-butanol as a "template", and the reaction temperature is 180 ℃, reaction time is 36 h, can successfully synthesize B phase vanadium dioxide VO2 powders which has a fibrous microscopic morphology. Selection of oxalic acid as a reducing agent, and the reaction temperature is 180 ℃, reaction time is 48 h, by varying the concentration of oxalic acid can prepare snowflake like, carambola like, and rod like B phase vanadium dioxide VO2 powders which have the special morphologies.When the reaction temperature is 260 ℃, reaction time is 48 h, we successfully prepared snowflake-like M phase vanadium dioxide VO2 powder.(4) We use the organic sol-gel method successfully prepared doped M phase vanadium dioxide VO2 films, among them one thin film doped with 1% molybdenum owns relatively good phase transition characteristics, the thickness of this thin film is about 200 nm, the phase Transition temperature is about 57 ℃, thermal hysteresis loop temperature width is about 2 ℃, and at the wavelength of 8 ~ 14 um the reflectance have a certain mutation.