  Novel imaging spin-filter techniques, which are based on low energy electron
diffraction, are currently of high scientific interest. To improve the
spin-detection efficiency a variety of new materials have been introduced in
recent years. A new class of promising spin-filter materials are represented by
multiferroic systems, as both magnetic and electric ordering exist in these
materials. We have investigated Fe/BaTiO3(001), which defines a prominent
candidate due to its moderate spontaneous polarization, for spin filter
applications calculating diffraction patterns for spin polarized electrons
incident on the Fe surface. Motivated by the fact that spin polarized low
energy electron diffraction is a powerful method for the determination of the
properties of surfaces we investigated the influence of switching the BaTiO3
polarization on the exchange and spin orbit scattering as well as on
reflectivity and figure of merit. This system obviously offers the possibility
to realize a multiferroic spin filter and manipulating the spin-orbit and
exchange scattering by an external electric field. The calculations have been
done for a large range of kinetic energies and polar angles of the diffracted
electrons considering different numbers of Fe monolayers.
