PUB - Publikationen an der Universität Bielefeld

A special LEED system has been constructed, in which the gun is movable in front of the grids and diffracted beams can be extracted through a probe hole in the screen. The polarization is subsequently measured by means of Mott scattering. The Au(110) surface is of particular interest, because it shows a reversible structure transition, which manifests itself in LEED intensities as a change from a (1 × 2) pattern at low temperatures to a (1 × 1) pattern at higher temperatures. For the (1 × 1) structure, spin polarization was measured, with values up to 70%, and calculated for a number of beams as a function of energy and scattering angle. Theoretical and experimental results are in reasonable agreement. In particular, the polarization is found to depend sensitively on geometrical, electronic and vibronic properties of the surface. The experimental work was sponsored by the Deutsche Forschungsgemeinschaft, Sonderforschungsbereich 128