INCIDENT BEAM EFFECTS IN AED (AUGER-ELECTRON DIFFRACTION) - THE CASE OF CU(001)

The incident beam effects in the Auger Electron Diffraction of the Cu( 001) surface have been studied through the anisotropy emission of the L(2,3)VV and the M(2,3)VV transitions. The spectra have been collected using a screened CMA In a polar scan for the two main direction [100] , [110] and in normal emission azimuthal scan. The low and high kineti c energy Auger lines show anisotropies spectra with very different beh aviour all over the polar angle scan, in particular around the 0 degre es emission we observe that the anisotropy signal is in total antiphas e. This is in very good agreement with the theoretical and the experim ental X-ray photoelectron diffraction. Although incident beam diffract ion should be sizeable, when the collection of the spectra is made wit h a standard CMA, our experiments evidence that incident beam diffract ion plays a negligible role when the electrons collection is made thro ugh a very small detection angle.