TEMPERATURE-DEPENDENCE OF THE ELECTRONIC AND VIBRATIONAL EXCITATIONS OF C-60 ADSORBED ON SI(100)-2X1

Electron spectroscopic studies of C-60 monolayers adsorbed on a Si(100 )-2 x 1 surface as a function of annealing temperature indicate three adsorption states. At room temperature C-60 interacts weakly with the surface and in consequence the electronic and vibrational excitations of the molecule are only slightly perturbed. Above 873 +/- 10 K change s in electronic and vibrational excitations indicate that, although th e molecule remains intact, the nature of the surface-molecule bond cha nges, leading to what may be regarded as a strongly chemisorbed 'precu rsor' state to cage opening and destruction. Beyond 1048+/-10 K the fu llerene molecules begin to break up, with some carbon atoms remaining on the substrate surface in the form of a carbide.