Adsorbate-Substrate Vibrational Modes of Benzene on Ag(110) Resolved with Scanning Tunneling Spectroscopy

J. I. Pascual; J. J. Jackiw; Z. Song; P. S. Weiss; H. Conrad; H.-P. Rust

doi:10.1103/PhysRevLett.86.1050

Adsorbate-Substrate Vibrational Modes of Benzene on Ag(110) Resolved with Scanning Tunneling Spectroscopy

J. I. Pascual, J. J. Jackiw, Z. Song, P. S. Weiss, H. Conrad, and H.-P. Rust

Phys. Rev. Lett. 86, 1050 – Published 5 February 2001

Abstract

Using a low temperature scanning tunneling microscope, we have detected low energy adsorbate-substrate (external or frustrated) vibrational modes of benzene molecules adsorbed on a Ag(110) surface. We demonstrate that such vibrations represent a fingerprint of the molecules' chemical state and environment; two different vibrational spectra are measured on molecules populating two different adsorption states. We also find that the distortion of the adsorption geometry of the molecules may give rise to the excitation of additional (initially hidden) modes. Important differences in the spatial distribution of the inelastic signal are also observed for these external modes.

Received 28 July 2000

DOI:https://doi.org/10.1103/PhysRevLett.86.1050

Authors & Affiliations

J. I. Pascual¹, J. J. Jackiw^1,2, Z. Song¹, P. S. Weiss², H. Conrad¹, and H.-P. Rust¹

¹Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
²Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802-6300