VIBRATIONAL PROPERTIES AND STRUCTURE OF <font>C</font>₆₀ THIN FILMS ON <font>Si</font>(111)-(7×7) AND GRAPHITE SURFACES

Abstract

We have investigated the vibrational modes of C 60 thin films adsorbed on the Si (111)-(7×7) and graphite surfaces using high-resolution electron energy-loss spectroscopy in combination with scanning tunneling microscopy (STM). The energy-loss spectra are different in energies and in oscillator strengths for the two surfaces. The differences are attributed to the surface morphology observed with STM. The relation between macroscopic dielectric theory manifested by electron energy loss and microscopic structure measured with STM is discussed in terms of dielectric function theory.