Zhejiang Univ, Dept Phys, Hangzhou 310027, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Lab Synchrotron Radiat, Beijing 100039, Peoples R China
Photoemission studies reveal the existences of metallic Rb4C60 and Rb5C60 surface phases on the top layer of C-60 single crystal. After Rb3C60 thin film with thickness of nanometers has formed on the (1 1 1) surface layers of the C-60 single crystal, the excess deposition of Rb atoms do not induce the bulk-like face-centered cubic to body-centered tetragonal or body-centered cubic structure transitions at room temperature. The large size Of C-60 molecule offers the surface vacancies for the formation of Rb4C60 and Rb5C60 monolayer that is further verified by Rb 3d core-level photoemission measurements. Valence band photoemission results exhibit the surface phases are metallic. (C) 2003 Elsevier B.V. All rights reserved.