Structure and optical property changes of sol‐gel derived VO 2 thin films

The semiconductor–metal phase change in VO 2 at approximately 67°C, which results in great changes in its optical, electrical, and magnetic properties, is described in detail. The synthesis of VO 2 thin films by the sol‐gel method is outlined and the structure and optical properties are characterized, including hysteresis phenomena in the transmittance–temperature and reflectivity–temperature plots. A mechanism of the phase change—confirmed to be the monoclinic‐to‐tetragonal rutile transition—is proposed based on coordinative field theory.