Semiconductor-metal phase transition in oxides of Magneli series: VO and V-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-

Abstract

A comparative analysis of the physical parameters of strongly correlated oxides VO and V2O3 has been carried out. It has been established that the semiconductor--metal phase transition in both VO and V2O3 has a complex Mott-Peierls character. Namely, as the temperature increases in both oxides, before the Peierls abrupt structural phase transition, the Mott phase transition, which is extended in temperature, take place. It has been discussed the reason for the fact that, despite the stabilization of the semiconductor phase by high-strength π-dimers or sigma-dimers, the temperatures of phase transitions are low (Tc=126 K (VO) and Tc=140 K (V2O3)). Keywords: Magnelis series, phase transformations, electron-electron correlations.