Magnetic Anisotropy
Mostrando 13-24 de 97 artigos, teses e dissertações.
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13. Magnetostricção e Anisotropia Magnética de filmes de Cobalto em substratos de vidro e silício / Magnetostricção and magnetic anisotropy of cobalt films on glass substrates and silicon
Este trabalho tem como objetivo estudar a magnetostricção e a anisotropia magnética de filmes finos de cobalto usando a técnica de Ressonância Ferromagnética. As amostras investigadas foram produzidas pela técnica de magnetron sputtering, depositadas sobre substratos de vidro e silício, com espessuras variando na faixa de 10 a 20 nm. Os valores efeti
Publicado em: 2011
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14. Multicamadas Ferromagnéticas Nanométricas Periódicas e Quasiperiódicas
We present a study of nanostructured magnetic multilayer systems in order to syn- thesize and analyze the properties of periodic and quasiperiodic structures. This work evolved from the deployment and improvement of the sputtering technique in our labora- tories, through development of a methodology to synthesize single crystal ultrathin Fe (100) films, to t
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/10/2010
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15. Anisotropias magnéticas em filmes finos de Co: Uma análise por magnetometria de torque / Magnetic anisotropies in Co thin films:An analysis by torque magnetometry
By studying the magnetic behavior of materials a very important parameter to be analyzed are the constants of anisotropy. They can be associated with an effective anisotropy energy or to a more specific one as, for example, the magnetocrystalline. During the thin films deposition by magnetron sputtering, an uniaxial effective anisotropy can be induced due to
Publicado em: 2010
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16. Dinâmica de paredes de domínios em microfios amorfos recobertos por vidro
Amorphous glass-coated microwires are materials with soft magnetic properties suitable for various technological applications, mainly magnetic sensors. One of the outstanding properties of microwires with positive magnetostriction is the magnetic bi-stability, that means, the inversion of the magnetization is done by one magnetic domain wall displacement alo
Publicado em: 2010
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17. Propriedades fisicas do monocristal fe/mgo(100) e estudo da expansao termica da superficie da ag(100)
In this work we have developed a way to grow Fe/MgO(100) monocrystals by magnetron sputtering DC. We investigated the growing in a temperature range among 100 oC and 300 oC. Structural and magneto-crystalline properties were studied by dierent experimental techniques. Thickness and surface roughness of the lms were investigated by atomic force microscopy, wh
Publicado em: 2010
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18. Modelagem da precipitação de MnS em aços elétricos de grão orientado
Grain oriented silicon steel has been used for electrical purposes since the beginning of the twentieth century. Their properties such as high permeability and resistivity reduce energy losses. The high permeability of these steels arises from a preferred orientation of grains in relation to the direction of rolling which leads to strong anisotropy of the ma
Publicado em: 2010
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19. Estudo por ressonância ferromagnética das anisotropias uniaxial e unidirecional em bicamadas e tricamadas magnéticas / Ferromagnetic resonance study of the anisotropies uniaxial and unidirectional magnetic bilayer and tricamadas
A técnica de ressonância ferromagnética (FMR) foi utilizada para estudar propriedades magnéticas de bicamadas NiO/Co, NiO/Py e Py/FeMn (Py = Ni81Fe19) e tricamadas Co/NiO/Co, com diferentes espessuras das camadas ferromagnética e antiferromagnética, depositadas pela técnica de dc magnetron sputtering na presença de campo magnético de 400 Oe. Os expe
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 15/04/2009
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20. The spin dynamics of molecular magnets beyond Kubo's linear response theory
The description of quantum dynamics of nanomagnets is a central issue in most applications proposed for those systems. In this paper, we put forward a modified perturbation approach to study the spin dynamics of a molecular magnet in the presence of time-dependent magnetic fields.The non-perturbed Hamiltonian H0, which defines the interaction picture, may be
Brazilian Journal of Physics. Publicado em: 2009-09
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21. Effects of dust charge variation on electrostatic waves in dusty plasmas with temperature anisotropy
We utilize a kinetic approach to the problem of wave propagation in dusty plasmas, taking into account the variation of the charge of the dust particles due to inelastic collisions with electrons and ions. The components of the dielectric tensor are written in terms of a finite and an infinite series, containing all effects of harmonics and Larmor radius. Th
Brazilian Journal of Physics. Publicado em: 2009-03
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22. Ferromagnetic resonance study of the anisotropies uniaxial and unidirectional magnetic bilayer and tricamadas / Estudo por ressonância ferromagnética das anisotropias uniaxial e unidirecional em bicamadas e tricamadas magnéticas
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 roo
Publicado em: 2009
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23. Ferromagnetic Resonance in Super-Lattice Nife/RU / Ressonância Ferromagnética em Super-Redes NiFe/Ru
The Ferromagnetic Resonance (FMR) technique was used to study the magnetic anisotropy of NiFe/Ru multilayers. The FMR spectra and absorption fields of multilayers with Ru layers thickness bellow 20 Å are the same as that of single monolayer films. Evidence of the coupling between the magnetic layers also is given by the fact that for the sample with Ru thic
Publicado em: 2009
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24. Estudo de anisotropias de UHECR s em dados do Observatorio Pierre Auger / Study of anisotropies of cosmic rays in data from the Pierre Auger
Almost a century after the discovery of cosmic radiation, their origin, composition, acceleration and propagation mechanisms in the universe is still unknown for the ultra-high energy component ( >~ 1018 eV). The mystery grows due to the suppression (GZK cutoff) in the ux of cosmic rays with energies E >~ 6 × 10 19 eV, caused by the interaction of these par
Publicado em: 2009