Berlin 2012 – wissenschaftliches Programm
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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 20.76: Poster
Dienstag, 27. März 2012, 12:15–15:15, Poster A
Ultrafast magnetization dynamics of FePt:Cu — •Daniel Steil1, Sabine Alebrand1, Oliver Schmitt1, Mirko Cinchetti1, Martin Aeschlimann1, Fabian Ganss2, Christoph Brombacher2, and Manfred Albrecht2 — 1Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern, Germany — 2Institute of Physics, Chemnitz University of Chemnitz, 09107 Chemnitz, Germany
L10 ordered FePt compounds with out of plane anisotropy are one future candidate as a storage layer for the next generation of hard disc drives, due to their very high anisotropy energy. As these compounds typically have very high coercivity, they are best used in combination with heat assisted recording (HAMR) [1]. We have studied the demagnetization dynamics in the alloy system FePt:Cu following impulsive laser excitation. In particular we also investigated the helicity dependence of the magnetization dynamics. By adding copper to FePt it is possible to tune anisotropy and Curie temperature, which allows to study the influence of both parameters on magnetization dynamics. We find a fast and strong demagnetization for all sample compositions, leading to a long lasting multidomain state for high enough excitation fluences in remanence. Additionally we observe a small influence of light helicity on the magnetization dynamics for at least one of the samples, whose origin will be discussed.
Funding by the EU within the FP7 project UltraMagnetron is kindly acknowledged.
[1] D. Weller et al., Annu. Rev. Mater. Sci. 30, 611-644 (2000)