Phase transition and correlation effects in vanadium dioxide

A complex concept concerning the multistage process of thermal semiconductor-metal phase transition in vanadium dioxide is proposed. According to the concept, the transition proceeds in three stages: two stages occurring in a system of strongly correlated electrons and one stage which reduces to transformation of the crystal lattice symmetry. These stages can be initiated individually by hydrogenating the polycrystalline VO$_2$ film, since hydrogenation selectively affects different stages of the phase transition.