Precise Orientation of a Single C60 Molecule on the Tip of a Scanning Probe Microscope.

ROM 2013-5
Author: C. Chiutu,(1) A. M. Sweetman,(1) A. J. Lakin,(1) A. Stannard,(1) S. Jarvis,(1) L. Kantorovich,(2) J. L. Dunn,(1) and P. Moriarty(1)
Institute: (1) School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom (2) Department of Physics, King’s College London, The Strand, London, WC2R 2LS, United Kingdom
Publication: PRL 108, 268302 (2012)
Instrument: LT STM

We show that the precise orientation of a C60 molecule which terminates the tip of a scanning probe microscope can be determined with atomic precision from submolecular contrast images of the fullerene cage. Although submolecular resolution of a tip-adsorbed C60 was achieved previously by Schull and co-workers (Nature Nanotech. 6, 23 (2010)), we demonstrate for the the first time that atomically resolved images of the fullerene cage at the apex of the probe can be acquired by non-contact atomic force microscopy at tip-sample separations where the molecule-substrate interaction potential is weakly attractive. Measurements of the C60—C60 pair potential acquired using a fullerene-terminated tip are in excellent agreement with theoretical predictions based on a pairwise summation of the van der Waals interactions between C atoms in each cage, i.e., the Girifalco potential [L. Girifalco, J. Phys. Chem. 95, 5370 (1991)].

Corresponding author:
A. Sweetman(1),, P. Moriarty (1),