IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Science Thursday Sessions
       Session SS2-ThM

Paper SS2-ThM5
Visualization of the Electronic Structure of Metal Surfaces with Scanning Tunneling Spectroscopy

Thursday, November 1, 2001, 9:40 am, Room 122

Session: Electronic Structure II
Presenter: J.I. Pascual, Fritz-Haber-Institut der Max-Planck Gesellschaft, Germany
Authors: J.I. Pascual, Fritz-Haber-Institut der Max-Planck Gesellschaft, Germany
Z. Song, Dalian Institute of Chemical Physics. China
J.J. Jackiw, Pennsylvania State University
M. Hansmann, Fritz-Haber-Institut der Max-Planck Gesellschaft, Germany
G. Ceballos, Fritz-Haber-Institut der Max-Planck Gesellschaft, Germany
H. Conrad, Fritz-Haber-Institut der Max-Planck Gesellschaft, Germany
K. Horn, Fritz-Haber-Institut der Max-Planck Gesellschaft, Germany
H.-P. Rust, Fritz-Haber-Institut der Max-Planck Gesellschaft, Germany
Correspondent: Click to Email
In this presentation we analyze the electronic structure of several metal surfaces with an in-creasing level of complexity: from the (111) sur-faces of noble metals, with isotropic s-p states, to anisotropic alloy surfaces like NiAl(110), where the influence of Ni d-states dominates its elec-tronic structure in the proximity of the Fermi level. The measurements are done in a low temperature scanning tunneling microscope, where the energy resolution and stability are greatly improved. The spatial dependence of the differential tunnel con-ductance in the proximity of scattering potentials like defect sites or step edges offers a direct way to access structural information on the electronic states of the surface. There, the electron wave phase is fixed at the defect position, producing oscillations in the spatial shape of the density of states in the defect vicinity. The wavelength of these oscillations in real space can be easily transformed to reciprocal space information by means of a Fourier transformation.@footnote 1@ We are going to show the capabilities of this transformation by analyzing surface states on both, the isotropic and anisotropic surface states. Band gap edges also may produce oscillations in the density of states, and therefore, are also ac-cessible. By measuring the differential conduc-tance in a large range of energies we reconstruct the states’ topology in the reciprocal space. The energy range is not limited to the proximity of the Fermi energy: we probe states up to the vacuum level. Above this point we also resolve information about the surface density of states by analyzing the shape of the field emission resonances. . @FootnoteText@@footnote 1@L. Petersen et al. Phys. Rev. B 57, R5868 (1998).