Regensburg 2007 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 22: Surface or Interface Magnetism
O 22.3: Vortrag
Dienstag, 27. März 2007, 11:45–12:00, H36
Magnon-enhanced intraband scattering on a d-band ferromagnet — •Anke Schmidt1,2, Fabian Giesen1, Martin Weinelt1,2, Martin Pickel1,3, and Markus Donath3 — 1Max-Born-Institut, Max-Born-Straße 2A, 12489 Berlin, Germany — 2Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin, Germany — 3Physikalisches Institut, Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
Experimental access to the spin-dependent decay processes of low-energy electrons in d-band ferromagnets remains a challenge despite advanced techniques such as spin-polarised electron energy loss spectroscopy [1] or spin-resolved two-photon photoemission of image-potential states (IPS). In a spin- and time-dependent photoemission study of thin iron and cobalt films, we have combined the advantages of both methods. The dispersing IPS electron is employed as observer or primary electron, thus effectively separating low-energy losses from direct decay into d-holes. We found that intraband decay on iron is not only much stronger than on cobalt, but also highly spin-dependent. We interpret this in terms of magnon-enhanced exchange scattering between opposite spin-bands, consistent with theoretical predictions [2] that spin-flip processes contribute significantly to the decay of minority electrons in iron.
[1] J. Kirschner, Phys. Rev. Lett. 55, 973 (1985)
[2] M. Plihal and D.L. Mills, Phys. Rev. B 58, 14407 (1998), V.P. Zhukov, E.V. Chulkov, and P.M. Echenique, Phys. Rev. Lett. 93, 096401 (2004).