1. Sincrotrone Trieste, S.S. 14 Km 163.5, 34149 Trieste, Italy
2. CNR-Institute for Complex Systems, Via Fosso del Cavaliere 100, 00133
Roma, Italy
3. Physics Department
and CENMAT, University of Trieste, Via
Valerio 2, 34127 Trieste,
Italy
4. IOM-CNR Laboratorio TASC, Area Science Park, 34149 Trieste, Italy
5. Capres A/S, 2800 Kgs. Lyngby, Denmark
6. Department
of Physics and Astronomy,
Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark