Imaging Phonon Excitation with Atomic Resolution

• Published in: Science (American Association for the Advancement of Science) Vol. 319; no. 5865; pp. 930 - 933
• Main Authors: Gawronski, H, Mehlhorn, M, Morgenstern, K
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 15.02.2008; The American Association for the Advancement of Science
• Subjects: Atoms; Atoms & subatomic particles; Condensed matter: structure, mechanical and thermal properties; Electric potential; Electron tunneling; Electron, positron and ion microscopes, electron diffractometers and related techniques; Electrons; Energy; Exact sciences and technology; Fees; Image reconstruction; Image resolution; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Lattice dynamics; Molecules; Phonons; Phonons and vibrations in crystal lattices; Physics; Spectrum analysis; Standing waves; Temperature; Scanning tunneling microscopy; Gold; Electron scattering; Inelastic scattering; Crystal faces; Copper; Electron spectrometry
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1152473

Inelastic electron tunneling spectroscopy at low temperatures was used to investigate vibrations of Au(111) and Cu(111). The low-energy peaks at 9 millielectron volts (meV) on Au(111) and 21 meV on Cu(111) are attributed to phonons at surfaces. On Au(111), the phonon energy is not influenced by the different stacking of the surface atoms, but it is considerably influenced by different atomic distances within the surface layer. The spatial variation of the phonon excitation is measured in inelastic electron tunneling maps on Au(111), which display atomic resolution. This atomic resolution is explained in terms of site-specific phonon excitation probabilities.