From to : The metal-insulator transition of the Magnéli phase

Institut für Physik, Universität Augsburg - 86135 Augsburg, Germany

Corresponding author: Udo.Schwingenschloegl@physik.uni-augsburg.de

Received: 12 September 2002
Accepted: 14 November 2002

Abstract

The metal-insulator transition (MIT) of 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 occurring simultaneously. The analysis is based on a unified point of view of the crystal structures of , , and . This allows to group the electronic bands into states behaving similarly to the dioxide or the sesquioxide. While the sesquioxide-like states show rather weak changes on entering the low-temperature structure, some of the dioxide-like states display splittings and shifts similar to those known from . The MIT of 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 .