From VO2 to V2O3: The Metal-Insulator Transition of the Magneli Phase V6O11

TL;DR

This study investigates the electronic structure changes during the metal-insulator transition of V6O11 using density functional theory, revealing similarities to VO2 and V2O3 and providing insights into the electronic states involved.

Contribution

It offers a unified analysis of V6O11's electronic and structural transitions, linking its behavior to related oxides VO2 and V2O3, and clarifies the role of specific electronic states in the MIT.

Findings

V6O11's MIT involves electronic changes similar to VO2 and V2O3.

Weak changes in sesquioxide-like V 3d_yz states across the transition.

Dioxide-like V 3d_x^2-y^2 states show splittings and shifts during MIT.

Abstract

The metal-insulator transition (MIT) of V6O11 is studied by means of electronic structure calculations using the augmented spherical wave method. The calculations are based on density functional theory and the local density approximation. Changes of the electronic structure at the MIT are discussed in relation to the structural transformations occuring simultaneously. The analysis is based on a unified point of view of the crystal structures of V6O11, VO2, and V2O3. This allows to group the electronic bands into states behaving similar to the dioxide or the sesquioxide. While the sesquioxide-like V 3d_yz states show rather weak changes on entering the low-temperature structure, some of the dioxide-like V 3d_x^2-y^2 states display splittings and shifts similar to those known from VO2. The MIT of V6O11 arises as a combination of changes appearing in both of these compounds. Our results shed new light onto the role of particular electronic states for the MIT of V2O3.