INFLUENCE OF ADSORBATES AND SUBSTRATE INTERDIFFUSION ON THE SPIN-DEPENDENT ELECTRON-SCATTERING OF FE AG(001) - EXPLORATION OF THE PARAMETERSPACE FOR AN ELECTRON-SPIN DETECTOR/

The elastic low-energy electron scattering of ferromagnetic Fe(001) fi lms on Ag(001) exhibits a strong spin dependency, an effect that has b een utilized for spin detection in electron spectroscopy. The quality of the substrate crystal, the morphology of the Fe film, and the expos ure to adsorbates all have a strong influence on the spin-dependent el ectron scattering. These effects are especially prominent at low elect ron energies. Annealing of the Fe layer leads to interdiffusion. We ob serve that Ag migrates through the Fe film and forms a thin layer at t he surface. Since the exchange asymmetry does not decrease, protection of the Fe film against residual gases by a Ag layer promises longer l ifetimes for a spin detector without a significant loss of detection e fficiency.