SPIN-POLARIZED PHOTOEMISSION FROM AMORPHOUS ALLOY SURFACES

Recent results on spin polarized photoemission and photon excited seco ndary electron emission from the surfaces of ferromagnetic amorphous a lloys Fe-B, Co-B and Fe-Y are reviewed. Spin resolved density of state s calculations suggest that the spin polarization profile is very sens itive to the theoretical model chosen, but experiments demonstrate tha t the spin up density dominates at the Fermi edge in the iron-based al loys, while the spin down density is greater in the cobalt alloy. Vari ation of photon energy from 15-110 eV allows polarization of sp states to be probed as well as d states and evidence for contributions to th e magnetic moment from Y in Fe60Y40 and B in Co77B23 are examined. Pho ton excited secondary electrons provide a flexible monitor of surface magnetization: relative contributions to the polarization from spin po larization in the conduction band and spin dependence of the mean free path are separated by studying the variation of electron polarization with the kinetic energy of emission. (C) 1998 Elsevier Science B.V.