C. Cepek(1), M. Sancrotti(1), G. Constantini(1), C. Boragno(2), and U. Valbusa(2) (1)Laboratorio Nazionale TASC-INFM, Padriciano 99, I 34012 Trieste, Italy. (2)INFM and Dipartimento di Física, Universita’ di Genova, Via Dodecaneso, Genova, Italy

Low-dimensional fullerene-based systems have received progressively increasing attention over the last years due to the possibility of tailoring exotic electronic and structural properties [1]. The electronic structure and the growth mode of room temperature deposited C₆₀ molecules on Ag(001) are studied as a function of annealing temperature over the 300-800 K range. The measurements have been done by means of ultraviolet valence band and core level photoemission spectroscopy and scanning tunneling microscopy. It is found that the C₆₀ molecules are chemical bonded to the Ag(001) surface even at room temperature deposition. The chemical bond changes when the film deposited ar toom temperature is annealed up to 670 K. At higher annealing temperature (T>750 K) the C₆₀ molecules desorb from the surface and partially fragment producing atomic carbon on the surface

[1]A. Goldoni, c. Cepek, E. Magnano, A. D. Laine, S. Vandre’, and M. Sancrotti, Phys. Rev. B 58 (1998), 2228