Selective resolution of phonon modes in STM-IETS on clean and oxygen-adsorbed Cu(100) surfaces

The observation of surface phonon dispersion using local probes can provide important information related to local structural and thermal properties. In this study, surface phonon modes on a Cu(100) surface were measured using the inelastic tunneling spectroscopy of scanning tunneling microscopy (STM-IETS) with atomically sharp tips. Different phonon modes were selectively measured depending on the structures of the probing tips or the surfaces. Two different surface phonon modes, at 19.0 meV on a clean Cu(100) surface and at 13.5 meV on an oxygen-adsorbed Cu(100) surface, are explained by the selection rules. Additionally, the spatial variation in STM-IETS showed surface stress relaxation.Comment: 19 pages, 4 figures, supplementary material with 2 figure

Selective resolution of phonon modes in STM-IETS on clean and oxygen-adsorbed Cu(100) surfaces

The observation of surface phonon using scanning probe microscopy can provide important information related to local structural and electrical properties. In this study, surface phonon modes on a Cu(100) surface were measured using inelastic tunneling spectroscopy of scanning tunneling microscopy. One phonon mode was measured at 3.6 meV on a clean Cu(100) surface. On an oxygen-adsorbed Cu(100) surface, another phonon mode was measured at 13.5 meV. This phonon mode was considered to be enhanced by the symmetry created by Cu-missing rows. The spatially varying d2I/dV2 map showed the effect of surface stress relaxation.© 2019 Published by Elsevier B.V.11sciescopu