BAND-STRUCTURE EFFECTS IN THE SPIN-POLARIZED AND ANGLE-RESOLVED AUGER-ELECTRON SPECTRA OF THE FE(001) SURFACE

Auger electron spectra for Fe L3VV transitions have been calculated fo r the pure Fe(001) surface and for the surface covered by a sulphur la yer c(2 x 2)S/Fe. The influence of different factors on the angular di stribution of the Auger electron intensity and its spin polarization i s studied and discussed. The shape of the angular dependence of the in tensity is determined by the crystal structure. It is modified by the sulphur layer. The order of magnitude of the spin polarization is dete rmined by the local magnetic moments at the iron sites, that is by ban d structure effects. The magnetic scattering at the surrounding atoms produces a fine structure which is nearly independent of the magnetic state of the emitter. Thus, there is nearly the same shape of the P-AE S curve for both systems considered. The Fe valence sub-bands give: qu ite different contributions to the spin polarization which are caused by the different occupation numbers and the quite different Auger matr ix elements. Comparing the spin polarization for energies of 2 eV and 4 eV, respectively, below the top of the Fe L3VV spectrum, strong diff erences are found which are due to those different weights. (C) 1998 E lsevier Science B.V. All rights reserved.