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| Magnetization Reversal of Exchange-biased Bilayers and Trilayers Probed using Front and Back LT-MOKE |
| Journal of Magnetics, Volume 14, Number 1, 31 Mar 2009, Pages 36-41 |
Ki-Yeon Kim*  (Neutron Science Division, Korea Atomic Energy Research Institute), Ji-Wan Kim(Department of Physics, Korea Advanced Institute of Science and Technology), Hyeok-Cheol Choi(Department of Physics, Inha University), Chun-Yeol You(Department of Physics, Inha University), Sung-Chul Shin(Department of Physics, Korea Advanced Institute of Science and Technology), Jeong-Soo Lee(Neutron Science Division, Korea Atomic Energy Research Institute) |
| Abstract |
| Magneto-optical Kerr effect (MOKE) magnetometry was used to investigate magnetization reversal dynamics in 30-nm NiFe/15-nm FeMn, 15-nm FeMn/30-nm CoFe bilayers, and 30-nm NiFe/(2,10)-nm FeMn/30-nm CoFe trilayers. The in-plane magnetization components of each ferromagnetic layer, both parallel and perpendicular to the applied field, were separately determined by measuring the longitudinal and transverse MOKE hysteresis loops from both the front and back sides of the film for an oblique incident s-polarized beam. The magnetization of the FeMn/CoFe bilayer was reversed abruptly and symmetrically through nucleation and domain wall propagation, while that of the NiFe/FeMn bilayer was reversed asymmetrically with a dominant rotation. In the NiFe/FeMn/CoFe trilayers, the magnetic reversal of the two ferromagnetic layers proceeded via nucleation and domain wall propagation for 2-nm FeMn, but via asymmetric rotation for 10-nm FeMn. The exchange-biased ferromagnetic layers showed the magnetization reversal along the same path in the film plane for the decreasing and increasing field branches from transverse MOKE hysteresis loops, which can be qualitatively explained by the theoretical model of the exchange-biased ferromagnetic/antiferromagnetic systems. |
| Keywords: exchange bias; asymmetric magnetization reversal; MOKE |
| DOI: 10.4283/JMAG.2009.14.1.36 |
| Full Text: PDF |
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