AVS 45th International Symposium
    Nanometer-scale Science and Technology Division Friday Sessions
       Session NS+AS-FrM

Paper NS+AS-FrM10
Nanoparticle Near-Field Spectroscopy by a Microscopically Narrow (Subnanometer) Electron-Beam

Friday, November 6, 1998, 11:20 am, Room 321/322/323

Session: Innovative Nanoscale Measurements
Presenter: H. Cohen, Weizmann Institute of Science, Israel
Authors: H. Cohen, Weizmann Institute of Science, Israel
T. Maniv, Technion, Israel
Y. Rosenfeld Hacohen, Weizmann Institute of Science, Israel
R. Tenne, Weizmann Institute of Science, Israel
O. Stephan, University of Paris-Sud, France
C. Colliex, University of Paris-Sud, France
Correspondent: Click to Email
Single nanoparticle near-field spectroscopy is performed in a scanning transmission electron microscope at non-intersecting beam-particle configuration. Separating the surface collective modes from the entire excitations spectrum, the energy loss signal is quantitatively accounted for, using a relatively simple theoretical model. Advantaged by the sub nanometer size of the e-probe, the highly controlled beam-surface distance introduces an effective window in momentum space, exposed to a long wavelength relativistic dispersion, which provides an enhanced sensitivity to beam and particle size effects. The spatial dispersion of the particle dielectric function, associated with the electronic band structure, is practically filtered out. "Particle spectroscopy", namely the selective excitation of modes which characterize the particle geometry and size, is available at selected beam-particle distances.