Magnetization Process
Mostrando 1-12 de 28 artigos, teses e dissertações.
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1. Giant Magneto Impedance Effect of Co-Based Metallic Fiber Under Bias Magnetic Field
The giant magneto impedance, GMI, effect of Co-based metallic fibers prepared by melt-extracted technology is investigated under different bias direct electrical current Ib. The GMI curves have single peaks which are symmetric about zero field at and below 1MHz. However, the bimodal GMI curves which have asymmetric peaks are observed when Ib is over 2mA at 0
Mat. Res.. Publicado em: 16/09/2019
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2. Diameter Dependence of Magnetic Properties of Co-based Metal Fibers
Naked Co68.25Fe4.5Si12.25B15 metal fibers with diameter from 25 µm to 100 µm are produced by melt extraction method. Significant diameter dependence of magnetic properties is studied. Their microstructure and magnetic properties of hysteresis loops and giant magneto impedance (GMI) effect at frequencies from 0.1MHz to13MHz are investigated. The results sho
Mat. Res.. Publicado em: 09/09/2019
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3. Comportamiento magnético del acero AISI 304 en ensayos de tracción uniaxial
ABSTRACT During the magnetization process of a ferromagnetic material, the magnetic domain walls are forced to move due to the magnetic field influence. The domain walls must overcome the stress produced by the pinning sites (grain boundary, dislocations, inclusions, etc.), producing discrete jumps in the magnetization. These jumps can be detected with a sen
Matéria (Rio J.). Publicado em: 19/07/2018
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4. Modificación de las propiedades estructurales, eléctricas y magnéticas del BiFeO3 por la incorporación de Ba y Nb
Bismuth ferrite (BFO) and Ba-Nb-substituted BFO with compositions Bi1-xBaxFeO3 (x= 0, 0.10, 0.15 y 0.20), BiFe1-yNbyO3 (y= 0, 0.03, 0.06 y 0.09) y Bi1-xBaxFe1-yNbyO3 (x= 0.10 (y= 0, 0.03, 0.06 y 0.09) powders were synthesized using the citrate-gel method. Infrared spectroscopy indicated shifting of Bi/Ba-O and Fe/Nb-O bond vibrations and a structural transit
Quím. Nova. Publicado em: 2017-02
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5. Thermal Transformation and Characterization of Synthetic Al-Substituted Maghemites (γ-Fe2-xAlxO3)
ABSTRACT Burning is a common practice in tropical areas and related changes in mineralogy might affect the chemical and physical behavior of soils. Maghemite is a common iron oxide in soils formed from basic rocks in tropical regions. This mineral and hematite are the main pigments in these soils and exhibit high magnetization stemming from the precursor mag
Rev. Bras. Ciênc. Solo. Publicado em: 03/11/2016
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6. Study of aluminum nitride precipitation in Fe- 3%Si steel
For good performance of electrical steels it is necessary a high magnetic induction and a low power loss when submitted to cyclic magnetization. A fine dispersion of precipitates is a key requirement in the manufacturing process of Fe- 3%Si grain oriented electrical steel. In the production of high permeability grain oriented steel precipitate particles of c
Mat. Res.. Publicado em: 11/06/2013
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7. Comportamento crítico da produção de entropia em modelos com dinâmicas estocásticas competitivas / Critical behavior of entropy production in models with competitive stochastic dynamics
We study kinetic phase transitions and the critical behavior of the entropy production in spin models with nearest neighbor interactions subject to two Glauber dynamics, which simulate two thermal baths at different temperatures. In this way, it is assumed that the system corresponds to a continuous time Markov process which obeys the master equation. Thus,
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/04/2011
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8. Propriedades de exchange bias e congelamento de spins de superfície em nanopartículas magnéticas
We present here magnetization measurements performed at low temperatures on magnetic nanocolloids based on 3.3 nm sized particles of manganese ferrite. This nanocolloid was obtained by a chemical core/shell strategy developed for the synthesis of ferro uids. Temperature dependence of the magnetization measurements allowed us to separate two contributions. On
Publicado em: 2009
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9. Propriedades magnÃticas do nanocompÃsito (Fe1-xCox)y(MnO)1-y
In the present work were investigated the magnetic properties of ferromagnetic nanocomposites (Fe1−xCox)y(MnO)1−y, x = 0.4 and 0.6 e y = 0.35, 0.65 and 1, produced by mechanical-alloying. Structural and morphological characterization were made by x-ray diffraction using Scherrer equation, Williamson-Hall plot and Rietveld refinement. The refineme
Publicado em: 2009
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10. Síntese, sinterização e caracterização de ferritas à base de Ni-Zn
Were synthesized different ferrites NixZn1-xFe2O4 (0,4 ≤ x ≤ 0,6) compositions by using citrate precursor method. Initially, the precursors citrates of iron, nickel and zinc were mixed and homogenized. The stoichiometric compositions were calcined at 350C without atmosphere control and the calcined powders were pressed in pellets and toroids. The
Publicado em: 2008
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11. Estudo de Impurezas de Carbono em Nanoestruturas de BN
In this work, we performed an analysis of the structural and electronic stability of nanostructures of Boron Nitride (BN), such as layers, tubes and cones, when doped with Carbon, through first-principles calculations as implemented in code SIESTA. We found that substitutional doping of Carbon for either a single Boron or a single Nitrogen atom produces sign
Publicado em: 2008
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12. Compósitos magnéticos baseados em hidrotalcitas para a remoção de contaminantes aniônicos em água
In this work the adsorption features of hydrotalcites (Al, Mg- CO3) and the magnetic properties of iron oxides have been combined in a composite to produce a magnetic adsorbent. These magnetic composites can be used as adsorbents for anionic contaminants in water and subsequently removed from the medium by a simple magnetic process. The magnetic hydrotalcite
Química Nova. Publicado em: 2007-10