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MA: Fachverband Magnetismus

MA 24: Magnetic Imaging and Scattering Techniques

MA 24.1: Vortrag

Mittwoch, 13. März 2013, 09:30–09:45, H22

Specular reflection from Ir(001) as efficient electron spin filter — •D. Kutnyakhov¹, P. Lushchyk¹, A. Fognini², D. Perriard², M. Kolbe¹, K. Medjanik¹, E. Fedchenko¹, S.A. Nepijko¹, H.J. Elmers¹, G. Salvatella², C. Stieger², R. Gort², T. Bähler², T. Michlmayer², Y. Acremann², A. Vaterlaus², F. Giebels³, H. Gollisch³, R. Feder³, C. Tusche⁴, A. Krasyuk⁴, J. Kirschner⁴, and G. Schönhense¹ — ¹Institut für Physik, Univ. Mainz — ²Lab. für Festkörperphysik, ETH Zürich, Switzerland — ³Universität Duisburg-Essen — ⁴MPI für Mikrostrukturphysik, Halle

A novel spin polarimeter is described that can transport a full image by making use of k-parallel conservation in low-energy electron diffraction from an Ir(001)-surface, extending our previous work on W(001) [1, 2]. This spin-filter crystal provides a high analyzing power combined with a *lifetime* in UHV of a full day. For specular reflection at 45° scattering angle we found a good working point at 37eV scattering energy that shows a broad maximum of 5eV usable width. A second one at about 10eV exhibits a narrower profile <1eV but much higher figure of merit. A relativistic layer-KKR SPLEED calculation shows good agreement with measurements. The asymmetry function (Sherman function) reaches values of 0.7 which considerably reduces the significance of spurious asymmetries. The novel detector has been used in a time-resolved experiment in the femtosecond region at the free-electron laser FLASH at DESY. [1] C. Tusche et al., APL 99 (2011) 032505; [2] M. Kolbe et al., Phys. Rev. Lett. 107 (2011) 207601

Funded by Stiftung Innovation(886 and 1038) and BMBF(05K12UM2)