SPIN-RESOLVED PHOTOEMISSION AND BAND-MAPPING IN EPITAXIAL FCC FE-CO ALLOYS ON CU(100)

The electronic properties of fee Fe-Co/Cu(100) were investigated by sp in-resolved photoelectron spectroscopy. At a fixed concentration a dis persion of the majority and minority bands with Delta(5)-symmetry towa rds higher binding energy along the Delta-axis of the Brillouin zone c ould be followed upon increasing photon energy, Upon variation of the concentration the spectra for the alloy films reveal a gradual shift o f the Delta(5) minority spin band through the Fermi level and a change of the sign of the spin polarization at the Fermi level in full agree ment with the expected tendency from Co to Fe. Such a behavior agrees with both a simple mixture of the Fe and Co electronic properties in a randomly mixed alloy film, and a chemical separation (clustering) of both constituents.