Exceptional properties of the magnetic interface state of Pd on Fe(1 1 0).

The magnetic characteristics of Pd thin films on Fe(1 1 0) were investigated by means of Magnetic Circular Dichroism in the Angular Distribution of photoelectrons (MCDAD). For uncovered Fe it was found that significant photoelectron intensity differences occur for electrons emitted from the 3d band near the Fermi level in the situation of a fixed helicity of the incoming circularly polarized radiation and opposite magnetization of the magnetic layer. The corresponding MCDAD asymmetry shows a strong dependence on the excitation energy in the VUV range and exhibits values up to about 10%. After deposition of Pd in the submonolayer regime up to a thickness of a few layers, the new features which are present in the photoemission spectra exhibit asymmetries, too. A strong hybridization takes place at the interface which is due to the intermixing of Pd 4d and Fe 3d states. This interface state shows no dispersion and no change of the asymmetry value for different photon energies. Additionally, the sign of the asymmetry is opposite to that of the Fe substrate. The reason is the strong hybridization which results not in a rigid band shift as found for less-interacting adsorbates but in new states being different in the majority and minority spin band. As a consequence, the interface layer exhibits an induced magnetic polarization. The structure near the Fermi energy exhibit the same sign of the asymmetry but with lower values. For a thickness of 3 monolayers the spectrum is comparable to bulk measurements and shows no MCDAD asymmetries in the entire binding energy region. [ABSTRACT FROM AUTHOR]