Molecular motion to substrate step edges

Surface Science, Vol. 446 (1-2) (2000) pp. 112-118
© 2000 Elsevier Science B.V. All rights reserved.
PII: S0039-6028(99)01118-8

Molecular motion to substrate step edges

J.H. Ferris¹, J.G. Kushmerick², J.A. Johnson³ and P.S. Weiss ^* stm@psu.edu

Department of Chemistry, 152 Davey Laboratory, University Park, PA 16802, USA

Received 15 July 1999; accepted 1 October 1999

Abstract

Upon adsorption at low temperature, isolated benzene molecules are attracted and move to step edges on the Ni{110} surface. The molecules had well-defined incident trajectories onto a Ni{110} crystal maintained at 4K so as to prevent thermally activated diffusion. We used low temperature scanning tunneling microscopy to measure the excess density of molecules at step edges, the adsorbate distributions on terraces, and the mean accommodation lengths. The incident azimuthal direction is not significant compared to the strong local attraction of the substrate step edges.

Keywords: Molecular motion; Nickel; Scanning tunneling microscopy; Step edges

¹Present address: Department of Chemistry, Princeton University, Frick Laboratory, Princeton, NJ 08544, USA.

²Present address: Biomolecular Materials and Interfaces, Sandia National Laboratories, Albuquerque, NM 87185, USA.

³Present address: Commonwealth Governor's School, Fredericksburg, VA 22405, USA.

^*Corresponding author. Fax: +1-814-863-5516