Theoretical spin polarization and intensity profiles in LEED from low-index surfaces of tungsten

Subsequent to the recent measurement of spin polarization effects in LEED, a relativistic LEED theory has been modified such as to facilitate computations for energies up to about 200 eV. Application to several low-index surfaces of tungsten yields intensity-energy profiles in good agreement with experiment. The calculated spin polarization profiles exhibit large maxima and show encouraging agreement with the as yet limited experimental data. Contraction of the top layer spacing with respect to the bulk spacing is found to produce drastic changes in parts of the polarization profiles. LEED spin polarization analysis could therefore provide a sensitive means of surface structure determination. Further, some polarization maxima coincide in energy with sizeable intensity values. This offers promising prospects for the construction of a low-energy spin polarization detector on a double diffraction basis and of an intense source of polarized electrons.