T. Kachel

Quantum size effects and the enhancement of the exchange splitting in ultrathin Co overlayers on Cu (100)

The spin dependent electronic structure of epitaxial Co overlayers on Cu (100) has been studied by spin and angle resolved photoemission with synchrotron radiation. Co layers with a thickness below 5 monolayers show an enhanced value of the exchange splitting at the center of the Brillouin zone due to quantum size effects. The experimental results are supported by FLAPW calculations for 1, 2 and 3 Co layers on Cu (100). These calculations show that the increase of the average exchange splitting is related to the enhancement of the magnetic moment in ultrathin Co layers.

Surface magnetism and electronic structure of ultrathin fcc Fe films

Spin- and angle-resolved photoemission show that a very similar development of the electronic structure occurs in fcc Fe films grown on Co(100) and on Cu(100). On both substrates the electronic structure displays distinct changes as a function of the thickness which correlate with the magnetic properties of the film. The measurement of the photoelectron spin polarization demonstrates that the surface region of Fe films on Co(100) as well as on Cu(100) is magnetically alive at all thicknesses.

Photoemission study of the Fe 3s spin resolved spectral distribution

Abstract The origin of the core level splitting in Fe 3s photoemission spectra has been investigated by spin resolved photoemission with synchrotron radiation. The Fe 3s spectral distribution is found to depend significantly on the spin orientation of the photoelectron. The spin polarization of the two split features in the Fe 3s spectra has been directly measured for the first time. The two spectral structures, separated by 4.4 eV, are characterized by large but opposite spin polarization. These results demonstrate that the exchange interaction is the main cause of the Fe 3s splitting.