Abstract
Epitaxial films of Cr were grown at 200 °C on Fe(100). The magnetic order of the Cr overlayers was studied by spin polarized electron energy loss spectroscopy (SPEELS). The exchange scattering asymmetry is large (negative) for the bare Fe surface and rapidly drops with increasing Cr coverage in the submonolayer range changing sign at around one monolayer Cr. This shows directly the antiferromagnetic coupling of the first Cr layer to the Fe substrate. With further increase in the Cr thickness the exchange asymmetry oscillates with a period of about 2 layers, thus proving directly the layer-by-layer antiferromagnetic order in the Cr films. The oscillation amplitude shows variations with thickness resembling features found in the magnetic coupling in Fe/Cr/Fe sandwiches. The SPEELS spectra show a maximum in the spin flip channels around 1.9 eV. This structure broadens with increasing Cr thickness. This large spin flip energy suggests a surface enhanced exchange splitting and an enhanced Cr surface moment.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
