TY - JOUR
T1 - Variation of Magnetization Dynamics of Co/Ni Multilayer by Capturing Magnetic Nanoparticles
AU - Otaki, Y.
AU - Kato, T.
AU - Okamoto, S.
AU - Kikuchi, N.
AU - Oshima, D.
AU - Iwata, S.
AU - Kitakami, O.
N1 - Funding Information:
ACKNOWLEDGMENT The authors would like to thank M. Kumazawa of Nagoya University for his assistance with the experiments. This work was partly supported by JSPS KAKENHI Grant Number 16H04328, 16K18091, 17H03249, 17K18878, and 17K19068 and in part by the Nagoya University Nanofab-rication Platform through the “Nanotechnology Platform Program” of the Ministry of Education, Culture, Sports, Science and Technology, Japan. A part of this paper was performed under the Research Program of “Dynamic Alliance for Open Innovation Bridging Human, Environment and Materials” in “Network Joint Research Center for Materials and Devices.”
Publisher Copyright:
© 1965-2012 IEEE.
PY - 2018
Y1 - 2018
N2 - [Co (0.29 nm)/Ni (0.71 nm)]10 multilayers were deposited on Ta (30 nm) and Pt (30 nm) buffer layers, and the variation of the magnetization dynamics by the adsorption of Fe3O4 nanoparticles was studied by vector network analyzer-ferromagnetic resonance method. The surface roughness of the Co/Ni multilayer was 0.52 nm, and significantly increased after the adsorption of the Fe3O4 nanoparticles which was captured by large field gradient on the demagnetized Co/Ni multilayer. The anisotropy field Hκ, damping constant α, and anisotropy distribution Δ Hκ of the Co/Ni on Ta buffer layer were 2.6 kOe, 0.012, and 0.32 kOe, respectively. By adsorbing of the Fe3O4 nanoparticles, the stray field from the nanoparticles Hnp was applied to the Co/Ni, and Hκ + Hnp was estimated to increase to 3.7 kOe. Moreover, α and Δ Hκ also increased to 0.020 and 0.42 kOe by the adsorption, respectively. Similarly, Hκ + Hnp,α, Δ Hκ of Pt buffered Co/Ni also increased from 2.4 kOe, 0.033, 0.43 kOe to 4.2 kOe, 0.055, 0.53 kOe, respectively. These results suggest that the adsorption of Fe3O4 nanoparticles significantly modifies the magnetization dynamics of Co/Ni multilayer.
AB - [Co (0.29 nm)/Ni (0.71 nm)]10 multilayers were deposited on Ta (30 nm) and Pt (30 nm) buffer layers, and the variation of the magnetization dynamics by the adsorption of Fe3O4 nanoparticles was studied by vector network analyzer-ferromagnetic resonance method. The surface roughness of the Co/Ni multilayer was 0.52 nm, and significantly increased after the adsorption of the Fe3O4 nanoparticles which was captured by large field gradient on the demagnetized Co/Ni multilayer. The anisotropy field Hκ, damping constant α, and anisotropy distribution Δ Hκ of the Co/Ni on Ta buffer layer were 2.6 kOe, 0.012, and 0.32 kOe, respectively. By adsorbing of the Fe3O4 nanoparticles, the stray field from the nanoparticles Hnp was applied to the Co/Ni, and Hκ + Hnp was estimated to increase to 3.7 kOe. Moreover, α and Δ Hκ also increased to 0.020 and 0.42 kOe by the adsorption, respectively. Similarly, Hκ + Hnp,α, Δ Hκ of Pt buffered Co/Ni also increased from 2.4 kOe, 0.033, 0.43 kOe to 4.2 kOe, 0.055, 0.53 kOe, respectively. These results suggest that the adsorption of Fe3O4 nanoparticles significantly modifies the magnetization dynamics of Co/Ni multilayer.
KW - Anisotropy field
KW - Co/Ni multilayers
KW - Feâ Oâ ., nanoparticles
KW - Gilbert damping
KW - ferromagnetic resonance (FMR)
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U2 - 10.1109/TMAG.2018.2832660
DO - 10.1109/TMAG.2018.2832660
M3 - Article
AN - SCOPUS:85047630181
SN - 0018-9464
VL - 54
JO - IEEE Transactions on Magnetics
JF - IEEE Transactions on Magnetics
IS - 11
M1 - 8365157
ER -