J. Phys. Soc. Jpn. 77, pp. 117-118 (2008) [2 Pages]
Proceedings of the International Symposium on Fe-Pnictide Superconductors

On the Electronic Structure of Electron Doped LaFeAsO1-xFx

+ Affiliations
1IFW Dresden P.O. Box 270016, 01771 Dresden, Germany2BESSY, Albert-Einstein-Strasse 15, 12489 Berlin, Germany3Humboldt-Universität zu Berlin, Institut für Physik, Newtonstrasse 15, 12489 Berlin, Germany4University Utrecht, Sorbonnelaan 16, 3584 CA Utrecht, Netherlands

We investigated the recently found superconductor LaFeAsO 1- x F x by X-ray absorption spectroscopy (XAS). A shift in the chemical potential is visible in both the Fe L 2,3 and O K edge spectra which emphasizes the importance of band effects and moderate correlations in these compounds. From experimental Fe L 2,3 edge spectra and charge transfer multiplet calculations we gain further information on important physical values such as hopping parameters, the charge transfer energy Δ, and the on-site Hubbard U . Furthermore we find the system to be very covalent with a large amount of ligand holes.

©2008 The Physical Society of Japan