Buckyball-substrate interactions probed by STM and AFM

Abstract

Submonolayers of buckyball molecules (C 60) on a gold substrate, deposited under ultrahigh-vacuum (UHV) conditions, have been imaged in air using scanning tunneling microscopy (STM) and atomic force microscopy (AFM). STM images show intramolecular contrasts within most individual C 60 molecules. AFM images of the C 60 molecules, often grouped in a hexagonal arrangement, show no atomic-scale features. A possible explanation for the presence or absence of the intramolecular contrasts in the images obtained with the STM and AFM, respectively, is given by a molecular orbital calculation.