Comparison of MEED- and XPD-angular patterns from the Cu(001)-surface

The scattering of medium energy electrons (E-kin = 1600 eV) is believed to produce angular intensity distributions similar to those of the X-ray photo electron diffraction experiment. We show here that, in a special experiment al geometry, very important differences between MEED and XPD angular distri butions arise. In these conditions, elastic Bragg-beams can persist up to m edium electron energies. We further demonstrate by scanning the incidence a ngle only that the incoming beam direction cannot be neglected. (C) 2001 El sevier Science B.V. All rights reserved.