Spin-resolved-photoemission-spectroscopy study of the giant resonance in Gd overlayers on Fe(100)

It is shown that insight into the giant resonance of the lanthanides can be obtained by spin- and energy-resolved photoelectron spectroscopy. Gd has been evaporated onto the Fe(100) surface in the monolayer and submonolayer range of coverage. The spin-dependent electronic structure has been studied by spin-resolved photoemission with photon energies from 70 eV up to the Gd 4d threshold. Within the well-known Fano-like giant resonance, the intensity of the Gd 4f (⁷F) signal shows an enhancement of about a factor of 20. The values of the total spin polarization of the Gd 4f (⁷F) photoemission peaks on resonance at h{ν}=152 eV and far away from the threshold at h{ν}=70 eV are compared. Both values are found to be identical within the experimental error. The results indicate that the amount of non-spin-conserving emission processes in the resonant regime is not increased with respect to the direct photoemission.