Anomalous electronic behaviour of Na superfullerides: theory and experiment
IBM Research Division, Zurich Research Laboratory CH-8803 Rüschlikon,
2 Scuola Normale Superiore and INFN - Piazza dei Cavalieri 7, I-56126 Pisa, Italy
3 Forschungszentrum Karlsruhe, Institut für Nukleare Festkörperphysik, Postfach 3640, D-76021 Karlsruhe, Germany
4 Institut für Festkörperforschung, IFW Dresden, Postfach 270016, D-01171 Dresden, Germany
Theory and experiment on NaxC60 agree that there is an anomalous trend as well as a limitation in the charge transfer from the sodiums to C60, for x>6. As revealed by both ab initio calculations and electron energy loss spectroscopy, the origin lies in the formation of interstitial states that trap a part of the excess electrons and that are neither C60- nor sodium-derived. This may well be a general characteristic of heavily doped intercalated fullerides and other cluster-based solid compounds.
PACS: 71.20.Tx – Fullerenes and related materials; intercalation compounds / 61.48.+c – Fullerenes and fullerene-related materials / 82.80.Pv – Electron spectroscopy for chemical analysis (photoelectron, Auger spectroscopy, etc.)
© EDP Sciences, 1996