Exchange and correlation effects in transition-metal oxides 3dn (n = 4, 5 and 6)
Language
en
Article de revue
This item was published in
Comptes Rendus. Chimie. 2003, vol. 6, n° 1, p. 135-145
Académie des sciences (Paris)
English Abstract
In order to clarify the competition of exchange and correlation energies vs crystal-field stabilisation energy, a simple approach is proposed. The exchange and correlation contributions are described on the base of Brandow ...Read more >
In order to clarify the competition of exchange and correlation energies vs crystal-field stabilisation energy, a simple approach is proposed. The exchange and correlation contributions are described on the base of Brandow and Kanamori's U, U′ and JH parameters. The dependence of the crystal field effect on site distortion has simply been modelled using a linear interpolation between undistorted and fully distorted sites. This approach leads to establish phase diagrams for d4, d5 and d6 cations, allowing us to predict the spin-state stability range depending on exchange (JH), crystal field (Dq) and distortion (k) parameters. It can be used to complement the Extended Hückel Tight Binding calculations of the electronic structure of materials having a noticeable ionic character such as 3d transition-metal oxides, in order to interpret the electronic behaviour, and, particularly, discuss the insulating-vs-metallic character of these oxides.Read less <
English Keywords
Exchange
Correlation
Crystal field
Transition metal oxides
Electronic structure
Metal–insulator transitions
Spin-state phase diagrams
Origin
Hal imported