Estudo por ressonância ferromagnética das anisotropias uniaxial e unidirecional em bicamadas e tricamadas magnéticas
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Data
2009-04-15
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Universidade Federal de Goiás
Resumo
The Ferromagnetic Resonance (FMR) technique at the X-band (~ 9.70 GHz) and Q-band (~ 34.0
GHz) was used to study the magnetic properties of NiO/Co, NiO/Py and Py/FeMn bilayers, and
Co/NiO/Co trilayers with different thicknesses, deposited by dc magnetron sputtering technique in
the presence of a 400 Oe magnetic field. The FMR experiments were all done at room
temperature using a high sensitivity Bruker ESP-300 spectrometer, with static scanning field and
usual modulation and phase sensitive detection techniques. The angular dependence of the inplane
resonance field allows the measurement of the exchange bias field for some NiO/Py
bilayers and the uniaxial anisotropy of the Co layer of NiO/Py bilayers and Co/NiO/Co trilayers.
The value of the exchange bias field of the NiO/Py bilayers varies from 29 Oe to 123 Oe while the
uniaxial anisotropy field of the Co layer, varies from 5 to 45 Oe. For Co/NiO/Co trilayers, the Co
in-plane uniaxial anisotropy field varies from 34 to 216 Oe. The out-of-plane angular dependence
of the resonance field allows the measurement of the effective magnetization and the g-factor,
which depend not only on the specific parameters of the samples, such as thickness of the
ferromagnetic layer, but also on the deposition conditions. The results obtained were compared
with known values in the literature and show the high sensitivity of the ferromagnetic resonance
technique in the study of the magnetic anisotropy and the exchange bias phenomena.
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Citação
SOUSA, Marcos Antonio de. Ferromagnetic resonance study of the anisotropies
uniaxial and unidirectional magnetic bilayer and tricamadas. 2009. 85 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de Goiás, Goiânia, 2009.