Electron Tunnelling at Surfaces of Mott Insulating d- and f-Metal Oxides: and Ab-Initio Interpretation of STM Images
Abstract
In this communication we describe recent progress in the first principles theoretical modelling of surface electronic structure and elevated temperature atomically-resolved STM images of surfaces of semiconducting d and f metal oxides. The presence of strong electron correlations in the 3d and 5j shells of metal ions in NiO, CoO and UO2 makes conventional computational methods based on the local spin density approximation (LSDA) of density functional theory unsuitable for ab initio calculations of the surface electronic structure of these oxides. By using the LSDA+U approach. which combines LSDA with the Hubbard U term, we explain the origin of the contrast reversal of experimental STM images of the NiO (001) surface. We also show how the symmetry of surface states is responsible for the order of magnitude difference in the contrast of STM images of NiO (001) and CoO (001) surfaces. and we describe how theoretical simulations make it possible to identify the atoms that are seen in STM images of the (111) surface of UO2.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 18, 1999
- Accession Number
- ADP012916
Entities
People
- A. P. Sutton
- G. A. Briggs
- M. R. Castell
- S. L. Dudarev
Organizations
- University of Oxford