Spin splitting of image-potential states on fcc Fe/Cu(100)

The ferromagnetic exchange splitting of the lowest image-potential states h as been measured for Fe films on Cu(100). The majority and minority spin co ntributions were separated using polarization-dependent two-photon photoemi ssion without magnetizing the sample. The results show an increased spin sp litting for decreasing film thickness in agreement with the increasing magn etic moment found by band structure calculations. The lifetime of the state s is between 3 fs and 15 fs with slightly shorter values for the minority s tate.