Characterization and Thermodynamic Analysis of VO2 Synthesized by NH4VO3

Abstract

A new process was developed for synthesizing vanadium dioxide (VO2) by pyrolyzing ammonium metavanadate (NH4VO3) in nitrogen flow. The chemical reaction in the synthesizing process was analyzed by thermodynamic calculations. X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were applied to characterizing the product. The experimental results indicated that VO2 microcrystal particles were successfully synthesized. The product VO2 presents two kinds of micro morphologies, torispherical and pentagonal prism. The phase transition mainly takes place at 337.8K and 341.8K. The average enthalpy of phase transition is 28.82 J/g.