Valence-band and core-level photoemission spectroscopy of LaFeAsO1-xFx

We have investigated the electronic structure of LaFeAsO(1-x)F(x) (x=0; 0.1; 0.2) by angle-integrated photoemission spectroscopy and local-density approximation (LDA)-based band-structure calculations. The valence band consists of a low-energy peak at E approximate to-0.25 eV and a broad structure around E approximate to-5 eV, which are in qualitative agreement with LDA. From the photon-energy dependence of these peaks we conclude that the former derives almost exclusively from Fe 3d states. This constitutes experimental evidence for the strong iron character of the relevant states in a broad window around E(F) and confirms theoretical predictions.