Accession Number:

AD0909521

Title:

Inelastic Low-Energy Electron Diffraction Measurements on Al(111)

Descriptive Note:

Technical publication

Corporate Author:

NAVAL WEAPONS CENTER CHINA LAKE CA

Personal Author(s):

Report Date:

1973-03-01

Pagination or Media Count:

19.0

Abstract:

An experimental study has been made of electrons in the energy range 40-80 eV inelastically scattered and diffracted from a clean Al111 surface. The surface is prepared by epitaxial vapor deposition on a Si111 single- crystal surface in ultrahigh vacuum immediately preceding the measurements. The inelastic electron intensity at a given energy loss and angle is obtained as the energy derivative of the amplified electron current from a Faraday collector having a retarding field analyzer and limited angular acceptance. The energy derivative comes from the digitally computed average of a repeatedly measured difference in dc signal accompanying a fixed increment in retarding field. Using this method inelastic angular and loss profiles at 15 degree incidence have been obtained in the vicinity of a Bragg maximum of the 00 elastic beam. The profiles show structure related to the surface and volume plasmon momenta by a two-step model of inelastic diffraction. Dispersion data inferred by applying this model to the loss-before-diffraction structure are compared with results from other sources. The surface plasmon dispersion obtained from inelastic low energy electon diffraction measurements shows promise as a new means of characterizing solid crystalline surfaces.

Subject Categories:

  • Physical Chemistry
  • Crystallography
  • Nuclear Physics and Elementary Particle Physics
  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE