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Ultrafast magnetization dynamics in the half‐metallic Heusler alloy Co 2 Cr 0.6 Fe 0.4 Al
Author(s) -
Wüstenberg JanPeter,
Steil Daniel,
Alebrand Sabine,
Roth Tobias,
Aeschlimann Martin,
Cinchetti Mirko
Publication year - 2011
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201147087
Subject(s) - demagnetizing field , condensed matter physics , magnetization , materials science , ferromagnetism , spin polarization , magnetization dynamics , ultrashort pulse , kerr effect , polarization (electrochemistry) , alloy , laser , magnetic field , physics , electron , metallurgy , optics , chemistry , quantum mechanics , nonlinear system
Ultrafast demagnetization upon excitation with intense laser pulses has been observed for a variety of ferromagnetic materials. In half‐metals, long demagnetization times are expected due to the band gap for one spin direction. We have investigated the theoretically half‐metallic Heusler alloy Co 2 Cr 0.6 Fe 0.4 Al (CCFA), using the time‐resolved magnetooptical Kerr effect. A demagnetization time in the range of typical transition metal ferromagnets with lower spin polarization has been found, while magnetization recovery proceeds on a slower time scale. The results are discussed in the context of recent models and experimental results. We propose that for Heusler alloys the initial stage of recovery could be a better measure for the spin polarization than the demagnetization time. A simple estimate leads to a bulk spin polarization value of 0.86 for CCFA.