Band structure of V₂O₃, and Ti₂O₃

Abstract

A previous calculation of the band structure of trigonal V₂O₃ and Ti₂O₃ by Nebenzahl and Weger is improved, taking a more rigorous treatment and including the effect of covalency. The agreement obtained with experimental results is good.

It is found that the width of the 3d band is about 9 eV for V₂O₃ and 11 eV for Ti₂O₃; this band is composed of a wide eσ and a narrow t_2g sub-band. The t_2g sub-band is the lower; its width is about 3 eV for V₂O₃ and 4 eV for Ti₂O₃, and the Fermi level lies within it. The density of states at the Fermi level is high for V₂O₃, and low for Ti₂O₃. It is shown that the inclusion of electron-electron interactions can bring about a metal-to-insulator transition in Ti₂O₃ in terms of a band-crossing model.