  Vanadium oxide films and fibers have been fabricated by the acetylacetonate
sol-gel method followed by annealing in wet nitrogen. The samples are
characterized by X-ray diffraction and electrical conductivity measurements.
The effects of a sol aging, the precursor decomposition and the gas atmosphere
composition on the annealing process, structure and properties of the films are
discussed. The two-stage temperature regime of annealing of amorphous films in
wet nitrogen for formation of the well crystallized VO2 phase is chosen: 1)
25-550 C and 2) 550-600 C. The obtained films demonstrate the metal-insulator
transition and electrical switching. Also, the effect of the
polyvinylpyrrolidone additive concentration and electrospinning parameters on
qualitative (absence of defects and gel drops) and quantitative (length and
diameter) characteristics of vanadium oxide fibers is studied.
