SPIN-RESOLVED AND HIGH-ENERGY-RESOLUTION XPS STUDIES OF COBALT METAL AND A COBALT MAGNETIC GLASS

The role of electron spin in photoelectric emission from the 2s, 2p(1/2), 2p(3/2), and 3p core levels of cobalt metal is investigated through a combination of spin-resolved x-ray-photoelectron spectroscopy (SRXPS) and high-energy-resolution XPS (HRXPS) studies. The sensitivity of the Co core-level spectra to a variation in the valence spin polarization is revealed by comparing the Co-metal data with SRXPS and HRXPS spectra from the amorphous cobalt-based ferromagnetic glass Co66Fe4Ni1B14Si15 The results demonstrate explicitly the role of intra-atomic exchange in deep-core-level photoemission from Co, and reveal core-hole spin dependencies to core-hole-induced electron-hole-pair excitation, to the L(1)L(2,3) V Coster-Kronig transition rate, and to the rates of Auger transitions involving the valence band. The data also suggest that the reduction of the cobalt magnetic moment in the Co66Fe4Ni1B14Si15 glass results from the transfer of majority-spin 3d electron density into the minority-spin 3d band caused by a hybridization-induced weakening of the 3d electron-electron interaction.