Y. Krockenberger (1,2), I. Fritsch (1), G. Christiani (1), H.-U.
  Habermeier (1), Li Yu (1), C. Bernhard (1), B. Keimer (1), and L. Alff (2)
  ((1) Max-Planck-Institute for Solid State Research, Stuttgart, (2) Institute
  of Materials Science, Darmstadt University of Technology)