ELECTRONIC AND GEOMETRIC STRUCTURE OF C-60 MOLECULES ON AU(001)

Abstract

The electronic and geometric structures of C60 molecular layers on the Au(001) surface were studied by scanning tunneling microscopy (STM) and spectroscopy (STS) and ultraviolet photoemission spectroscopy (UPS). Due to the lattice mismatch between the overlayer C60 and the substrate Au (100)-(5 X 20) surface, a uniaxial stress is applied to the overlayer along the [110] direction, resulting in several types of oblique lattices. The electron charge density around a C60 molecule appears to be an ellipsoid due to the modified electron charge density by the uniaxial stress. The molecules can be considered to be chemisorbed on the Au substrate by the UPS and STS data. Charge transfer from the substrate to the molecules and intermolecular bonding under stress were observed in STM and STS data.