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MA: Fachverband Magnetismus
MA 55: Poster II
MA 55.38: Poster
Friday, April 4, 2014, 10:30–13:30, P2
Ultrafast magnetization dynamics of Copper-doped FePt thin films for different Copper contents and fluences. — •Oliver Schmitt1, Daniel Steil1, Sabine Alebrand1, Stefan Mathias1, Mirko Mirko1, Martin Aeschlimann1, Fabian Ganss2, Christoph Brombacher2, and Manfred Albrecht2 — 1Department of Physics and Research Center OPTIMAS, TU Kaiserslautern, 67663 Kaiserslautern, Germany — 2Institute of Physics, Chemnitz University of Technology, 09107 Chemnitz, Germany
Future magnetic data storage devices require high density information packing. A typical material is an FePt thin film with high perpendicular magnetic anisotropy [1]. It is chemically ordered in the L10 phase. Here we investigate this material doped with different Cu contents from 15 to 25 percent using the femtosecond time-resolved magneto-optical Kerr-Effect. For all samples the speed of demagnetization increases very strongly for the highest magnetization quenchings. This behaviour has been proposed for 3d ferromagnets like Ni oder Co [2]. Moreover, we find for the FePt:Cu sample with 25% Cu a transient ferromagnetic-like state on ultrafast and picosecond timescales.
[1] S. H. Sun, C. B. Murray, D. Weller, L. Folks and A. Moser, Science 287, 1989 (2000). [2] B. Koopmans, G. Malinowski, F. Dalla Longa, D. Steiauf, M. Fähnle, T. Roth, M. Cinchetti and M. Aeschlimann, Nature Materials 9, 259*265 (2010)