title: Observing spin polarization of individual magnetic adatoms.
abstract: We have used spin-polarized scanning tunneling spectroscopy to observe the spin polarization state of individual Fe and Cr atoms adsorbed onto Co nanoislands. These magnetic adatoms exhibit stationary out-of-plane spin polarization, but have opposite sign of the exchange coupling between electron states of the adatom and the Co island surface state: Fe adatoms exhibit parallel spin polarization to the Co surface state while Cr adatoms exhibit antiparallel spin polarization. First-principles calculations predict ferromagnetic and antiferromagnetic alignment of the spin moment for individual Fe and Cr adatoms on a Co film, respectively, implying negative spin polarization for Fe and Cr adatoms over the energy range of the Co surface state.
authors.affiliation: Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Yayon
authors.forename: V W
authors.initials: VW
authors.lastname: Brar
authors.forename: L
authors.initials: L
authors.lastname: Senapati
authors.forename: S C
authors.initials: SC
authors.lastname: Erwin
authors.forename: M F
authors.initials: MF
authors.lastname: Crommie