Magnetic Field Configuration
Mostrando 1-12 de 35 artigos, teses e dissertações.
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1. Crescimento, estrutura e magnetismo de filmes ultrafinos de Ni depositados sobre Pd(100)
In this work, the growth mode, the structure and the magnetic behavior of ultrathin Ni films epitaxially grown over Pd(100) were investigated using in-situ experimental techniques ass RHEED, LEED, AES, MBE and MOKE, and ex-situ VSM. The objective was to study the influence of the stress induced by the lattice parameter mismatch of the materials (10,4%), the
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/02/2012
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2. Coherent and incoherent radiation from free-electron lasers with an axial guide field
The spontaneous and induced emission from a free-electron laser is treated for the case in which an axial magnetic field is imposed in addition to the helical, axially periodic wiggler magnetic field. The classes of possible single-particle trajectories in this configuration are discussed, and the results are applied to a calculation of the incoherent radiat
Publicado em: 2011
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3. Optimizing the e-beam profile of a single carbon nanotube field emission device for electric propulsion systems
Abstract: Preliminary studies on field emission (FE) arrays comprised of carbon nanotubes (CNT) as an electron source for electric propulsion system show remarkably promising results. Design parameters for a carbon nanotube (CNT) field-emission device operating on triode configuration were numerically simulated and optimized in order to enhance the e-beam fo
J. Aerosp. Technol. Manag.. Publicado em: 2010-04
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4. Effect of an columnar defect on vortex configuration in a superconducting mesoscopic sample
In this work we investigate the vortex dynamics in a square mesoscopic superconducting cylinder in the presence of an applied magnetic field parallel to its axis. The rectangular cross-section of the sample is L² and an engineered columnar defect of area d² at the center is taken into account; L = 12ξ(0) for all simulations while d varies discretely from
Brazilian Journal of Physics. Publicado em: 2009-12
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5. 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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6. Signatures of two distinct driving mechanisms in the evolution of coronal mass ejections in the lower corona / Assinaturas de dois mecanismos distintos na evolução de ejeções de massa coronal na baixa coroa
Coronal mass ejections (CMEs) are the major driver for space weather disturbances. Their physical mechanisms and their influence on the geospace environment are the subject of active research and debate. Our goal is to understand how the initial magnetic configuration of a CME affects its evolution through the lower corona, until 6R⊙. We compare ou
Publicado em: 2009
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7. Construção de uma armadilha magneto-ótica para aplicações em informação quântica e física atômica / Construction of a Magnet-Optical Trap for Aplications at Quantum Information and Atomic Physics
We built a magneto-optical trap (MOT) for rubidium as a first step for the trapping of a cloud of cold atoms in a periodic potential formed by light beams. This system will be used for experiments in atom physics, with possible applications in quantum information. A MOT is necessary to avoid the problems imposed by the thermal agitation of the atoms to the m
Publicado em: 2009
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8. Signatures of two distinct driving mechanisms in the evolution of coronal mass ejections in the lower corona / Assinaturas de dois mecanismos distintos na evolução de ejeções de massa coronal na baixa coroa
As ejeções de massa coronal (coronal mass ejections - CMEs) são as maiores causadoras das perturbações do clima espacial. Seus mecanismos físicos e sua influência no ambiente geoespacial são foco importante em debates e pesquisas. Nosso objetivo é compreender como a configuraçãoo magnética inicial da CME afeta sua evolução na baixa coroa, até
Publicado em: 2009
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9. Microwave absorption properties of Co, Cu, Zn: substituted hexaferrite polychloroprene nanocomposites
The magnetic behavior and its relationship with microwave absorbing properties have been investigated for doped Z-type barium hexaferrites (Ba3Co1.3Zn0.3Cu0.4Fe 24O41)/ polychloroprene (CR) nanocomposites. Simultaneous substitutions by Co2+, Cu2+, and Zn2+ ions make possible the use of these materials as RAMs, due to the frequency dependence of µr* (permeab
Materials Research. Publicado em: 2008-09
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10. Magneto-tunelamento ressonante em super-redes de GaAs/AsGaAs
In this thesis we present three works in weakly coupled semiconductor superlattices of GaAs/AlGaAs. In the first work we present an investigation of the electric field domain configuration in the sequential tunneling regime in weakly coupled superlattices in the presence of a magnetic field applied parallel to the quantum well layers. We show that, for an ap
Publicado em: 2008
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11. Chaotic transport in plasmas / Transporte caótico em plasmas
This work presents a study of the particle transport through the edge of a plasma cofined in a tokamak. A model, with an infinite number of drift waves superposed to an equilibrium electrostatic potential, in addition to an uniform magnetic field, is introduced, what puts the problem in the form of mappings. Two mappings are analysed, viz. the standard map a
Publicado em: 2008
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12. Propriedades físicas de bicamadas magnéticas
The magnetic order of bylayers composed by a ferromagnetic film (F) coupled with an antiferromagnetic film (AF) is studied. Piles of coupled monolayers describe the films and the interfilm coupling is described by an exchange interaction between the magnetic moments at the interface. The F has a cubic anisotropy while the AF has a uniaxial anisotropy. We ana
Publicado em: 2007