SPIN-RESOLVED X-RAY PHOTOEMISSION FROM FERROMAGNETIC NICKEL

Spin-resolved x-ray photoelectron-spectroscopy (SRXPS) studies of metallic-Ni core-level and valence-band photoemission are reported. Prominent spin polarizations are observed for all main components and satellites. A spin-dependent splitting of 0.38 eV is observed for the main Ni 3s component. The Ni 3s 6-eV satellite, as well as a secondary satellite located ∼14 eV from the main 3s peak, both display a nearly 100% majority-spin polarization. Analogous results are found for the Ni 2s level. The 6- and 14-eV satellites are assigned to final states derived from the 1G and 1S states, respectively, of a local ∼3d8 final-state valence configuration that is created by the shakeup of a-spin 3d electron to states above Ef. The manifestation of these phenomena in SRXPS studies of the Ni valence band, 3p, 2p3/2, and 2p1/2 core levels is presented and discussed. The SRXPS data are consistent with an itinerant-electron extra-atomic screening model in Ni involving both unoccupied pure 3d states and unoccupied, unpolarized, and hybridized 3d-4sp states. Final-state occupation of these states following photexcitation leads qualitatively to a final-state Ni 3d valence configuration of ∼50% 3d9 and ∼50% 3d10. The 3d9 configuration is the origin of the satellite production in Ni. © 1995 The American Physical Society.