Spin-dependent plasmons excitation in Fe layer on W(110) and their decay via electron emission

Abstract

Secondary electron emission spectra excited by spin-polarized electrons from a 5 ML Fe film on W(110) substrate were measured at the specular reflection geometry with the incident angle of 72° and various primary energies. Each spectrum was measured at two spin polarizations of the incident beam: with a polarization vector parallel and antiparallel to the magnetization vector of the Fe film, Yup(E) and Ydown(E). Using these two spectra, the asymmetry spectrum can be calculated as A(E) = (Yup(E) − Ydown(E))/(Yup(E) + Ydown(E)). We observed a true secondary emission feature in the asymmetry spectra at the energy (18–19) eV. We suggest that the mechanism responsible for that feature involves a spin-dependent plasmon excitation in the Fe film with its subsequent decay via electron emission.