Low-energy electron diffraction intensities from the clean copper (001) surface

Abstract

Experimental absolute intensity curves of the 00, 11, 20 and 22 diffraction beams from a clean copper (001) surface obtained for incident electron energies 1–600 eV are presented. A complete band gap extending to about 2 eV above the vacuum level in the electron energy band structure for copper accounts for most intense peak in the curves: the first Bragg peak around 1 eV in the 00 beam intensity. With increasing electron energy the peak intensities decrease and the peak widths increase. In the electron energy region 30–140 eV strong multiple scattering gives rise to intense secondary Bragg peaks and unsymmetrical peaks in the curves. These effects are due to large atomic scattering cross section of the copper atoms probably related to the 3p and 3s core states.