Berlin 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 20: Poster I - Biomagnetism, FePt Nanoparticles, Magnetic Particles/Clusters, Magnetic Materials, Magnetic Semiconductors, Half-metals/Oxides, Multiferroics, Topological Insulators, Spin structures/Phase transitions, Electron theory/Computational micromagnetics, Magnetic coupling phenomena/Exchange bias, Spin-dependent transport, Spin injection/spin currents, Magnetization/Demagnetization dynamics, Magnetic measurement techniques
MA 20.72: Poster
Dienstag, 27. März 2012, 12:15–15:15, Poster A
Element-resolved Ultrafast Spin Dynamics in Multi-component Ferromagnets and Ferrimagnets — •Andrea Eschenlohr1, Ilie Radu1,2, Christian Stamm1, Kadir Vahaplar2, Torsten Kachel1, Niko Pontius1, Rolf Mitzner1, Karsten Holldack1, Alexander Föhlisch1, Florin Radu1, Richard F. L. Evans3, Thomas A. Ostler3, Johan Mentink2, Roy W. Chantrell3, Arata Tsukamoto4,5, Akiyoshi Itoh4, Andrei Kirilyuk2, Alexey V. Kimel2, and Theo Rasing2 — 1Helmholtz Zentrum Berlin für Materialien und Energie GmbH, Germany — 2Radboud University Nijmegen, The Netherlands — 3University of York, UK — 4Nihon University, Chiba, Japan — 5Japan Science and Technology Agency, Saitama, Japan
With 100 fs soft x-ray pulses generated by the Femtoslicing facility at the BESSY II storage ring we measure element-resolved transient x-ray magnetic circular dichroism in ferromagnetic NiFe alloys, as well as ferrimagnetic GdFeCo alloy after laser excitation. We find time constants of demagnetization that are not only different for each magnetic sublattice in our alloy samples, but also different from the time constants found for respective pure element samples. Supported by phenomenological considerations and atomistic simulations we conclude that sub-picosecond magnetization dynamics is sensitive to both the magnetic moment and exchange interaction between the sublattices in multi-component magnets.