•H.-G. Boyen¹, K. Fauth², B. Stahl³, P. Ziemann¹, G. Kästle¹, F. Weigl¹, F. Banhart⁴, M. Heßler², G. Schütz³, N.S. Gajbhiye⁵, J. Ellrich⁶, H. Hahn⁶, M. Büttner⁷, M.G. Garnier⁷ und P. Oelhafen^7
6Fachbereich Material- und Geowissenschaften, Petersenstr. 23, TU Darmstadt, D-64287 Darmstadt
⁷Institut für Physik, Universität Basel, Klingelbergstr. 82, CH-4056 Basel
¹Abteilung Festkörperphysik, Universität Ulm, D-89069 Ulm
²Experimentelle Physik IV, Universität Würzburg, Am Hubland, D-97074 Würzburg
³MPI für Metallforschung, Heisenbergstraße 1, D-70689 Stuttgart
⁴Zentrale Einrichtung Elektronenmikroskopie, Universität Ulm, D-89069 Ulm
⁵Institut für Nanotechnologie, Forschungszentrum Karlsruhe, D-76021 Karlsruhe

Ordered arrays of well separated and atomically pure FePt nanoparticles (diameter 3.7 nm) have been prepared under UHV conditions by employing a combination of oxygen/hydrogen plasmas allowing to completely remove the organic ligands which are present after particle synthesis. The plasma treatments conserve, however, the order of the particle arrangement. This enables us to investigate, for the first time, the electronic structure and the magnetic properties of bare, ligand-free fcc FePt particles by means of X-ray induced photoelectron spectroscopy (XPS) and X-ray Magnetic Circular Dichroism (XMCD), respectively. First results about the electronic density of states and the magnetic behavior of the nanoparticle array will be presented.