Observing spin polarization of individual magnetic adatoms.
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.
Yayon
Y
Y
Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA.
Brar
V W
VW
Senapati
L
L
Erwin
S C
SC
Crommie
M F
MF