TY - JOUR
T1 - Magnetization dynamics in CoFeB buffered perpendicularly magnetized Co/Pd multilayer
AU - Sajitha, E. P.
AU - Walowski, Jakob
AU - Watanabe, D.
AU - Mizukami, S.
AU - Wu, Feng
AU - Naganuma, Hiroshi
AU - Oogane, Mikihito
AU - Ando, Yasuo
AU - Miyazaki, T.
N1 - Funding Information:
This work was supported in part by a Grand-in-Aid for Scientific Research and in part by a Grant for Industrial Technology Research from NEDO. The work of J. Walowski was supported by a scholarship from DAAD.
PY - 2010/6
Y1 - 2010/6
N2 - The magnetic properties of CoFeB buffered [Co(0.3 nm)/Pd(x nm)]6 multilayer films have been investigated. It is found that the magnetic properties of the multilayer depended on the Pd thickness and for thickness below 0.5 nm no perperdicular anisotropy is observed. Magnetization dynamics in perpendicularly magnetized CoFeB-[Co/Pd] multilayer films are investigated using time-resolved magneto-optical Kerr effect (TRMOKE). The variation of precession frequency with external magnetic field for different palladium thickness is quantitatively understood using the macrospin approximation of the Landau-Lifshitz-Gilbert equation of motion. The Gilbert damping constant α, in the range 0.040.1, varying with the palladium thickness is reported. The observed α value is comparable to the damping coefficient of bulk Ni, and much lower than the reported values for perpendicularly magnetized films. The CoFeB buffer layer with in-plane anisotropy appears to significantly affect the precession frequency and thus the damping constant of the films.
AB - The magnetic properties of CoFeB buffered [Co(0.3 nm)/Pd(x nm)]6 multilayer films have been investigated. It is found that the magnetic properties of the multilayer depended on the Pd thickness and for thickness below 0.5 nm no perperdicular anisotropy is observed. Magnetization dynamics in perpendicularly magnetized CoFeB-[Co/Pd] multilayer films are investigated using time-resolved magneto-optical Kerr effect (TRMOKE). The variation of precession frequency with external magnetic field for different palladium thickness is quantitatively understood using the macrospin approximation of the Landau-Lifshitz-Gilbert equation of motion. The Gilbert damping constant α, in the range 0.040.1, varying with the palladium thickness is reported. The observed α value is comparable to the damping coefficient of bulk Ni, and much lower than the reported values for perpendicularly magnetized films. The CoFeB buffer layer with in-plane anisotropy appears to significantly affect the precession frequency and thus the damping constant of the films.
KW - Fast magnetization dynamics
KW - Gilbert damping constant
KW - Magnetic multilayers
KW - Magnetoresistive random access memory (MRAM)
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U2 - 10.1109/TMAG.2009.2038929
DO - 10.1109/TMAG.2009.2038929
M3 - Article
AN - SCOPUS:77952831813
SN - 0018-9464
VL - 46
SP - 2056
EP - 2059
JO - IEEE Transactions on Magnetics
JF - IEEE Transactions on Magnetics
IS - 6
M1 - 5467527
ER -