Mechanism of hydrogen effect on the phase transition in V$_{2}$O$_{3}$ films

It is shown that in hydrogenated films of vanadium sesquioxide there is an excess of free electrons in comparison with nonhydrogenated films. This leads to a shift of the temperature hysteresis loops of the insulator-metal phase transition to the region of low temperatures, that is, to a decrease in the critical temperature $T_c$ of the phase transition. The interpretation of the results is based on the fact that V$_{2}$O$_{3}$ is a strong correlated material, and the phase transition in it is complex. Namely, the electronic Mott transition initiates the Peierls structural transition. It is shown that hydrogen atoms are localized on oxygen ions and form additional $\sigma$ bonds with them. Thermal destruction of these bonds leads to an increase in the concentration of free electrons in the conduction band of hydrogenated V$_{2}$O$_{3}$ films and initiates the correlation narrowing of the band gap.