Coercivity
Mostrando 13-24 de 37 artigos, teses e dissertações.
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13. Facile synthesis of inverse spinel NiFe2O4 nanocrystals and their superparamagnetic properties
Spinel NiFe2O4 nanocrystals have been obtained by means of a novel composite-hydroxide-salt-mediated approach, which is based on a reaction between metallic salt and metallic oxide in the solution of composite-hydroxide-salt eutectic at ~225 ºC and normal atmosphere without any organic dispersant or capping agent. The obtained products are characterized by
Mat. Res.. Publicado em: 22/11/2012
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14. Performance of single wire earth return transformers with amorphous alloy core in a rural electric energy distribution system
In this paper are presented some considerations about the performance of single wire earth return amorphous alloy core transformers in comparison with conventional silicon steel sheets cores transformers used in rural electric energy distribution network. It has been recognized that amorphous metal core transformers improve electrical power distribution effi
Mat. Res.. Publicado em: 08/05/2012
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15. Modelamento do efeito do tamanho de grão sobre o campo coercivo de aços elétricos. / Modelling the influence of grain size upon coercivity of electrical steel.
Chapas de aço elétrico (0,7% Si e 0,3% Al) foram laminadas a diferentes graus de deformação e recozidas (760º C, 2h) de modo a obter diferentes tamanhos de grão por recristalização. Um outro conjunto de chapas do mesmo material foi recozido a tempos e temperaturas diferentes de modo a obter tamanho de grão variado por crescimento de grão. Os tamanh
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 17/06/2011
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16. SÍNTESE E CARACTERIZAÇÃO DE NiFe2O4 E EFEITOS DA DOPAGEM NA MAGNETIZAÇÃO DE SATURAÇÃO. / SYNTHESIS AND CHARACTERIZATION OF NiFe2O4 AND EFFECTS OF DOPING IN MAGNETIC SATURATION.
The ferrites are a wide class of ferrimagnetic materials with great technological importance and are studied extensively for many decades. Their remarkable magnetic characteristics make it an element often used in induction transformers by his high magnetic permeability, high values of saturation magnetization and low coercivity, resulting in smaller losses
Publicado em: 2011
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17. Effect of Mo interlayer on magnetic properties of exchange coupled Sm-Co/Fe bilayers
Sm-Co/Fe, hard/soft magnetic bilayers have been fabricated on 70 nm Cr buffered Si (100) substrate by dc and rf magnetron sputtering and annealed at 525O C for 30min. Very thin Mo layers (0-0.7 nm) were introduced between Sm-Co and Fe layers. The samples were analyzed by X-Ray Diffraction (XRD) and Alternating Gradient Magnetometer (AGM). All of the samples
Brazilian Journal of Physics. Publicado em: 2010-06
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18. Structure, morphology and magnetism of an ultra-thin [NiO/CoO]/PtCo bilayer with perpendicular exchange bias
Electronic and magnetic properties of nanoscale materials are closely related to the atomic arrangement at the interface shared by different chemical elements. A very precise knowledge of the surface/interface structure is then essential to properly interpret the new properties coming out. Of a particular interest is the relationship between structure, morph
Brazilian Journal of Physics. Publicado em: 2009-04
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19. 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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20. Modelo de Preisach e análise FORC aplicados a filmes com exchange-bias / Preisach model and Forc analysis applied to exchang biased films
In this work, thin films of Si[100]/buffer/NiFe/FeMn/Ta (buffer = Cu; Ta) and spin valves of Si[100]/Cu/NiFe/Cu/NiFe/FeMn/Ta were produced via sputtering and their magnetic behavior were studied by First Order Reversal Curves (FORCs) analysis. A Preisach Model with Exchange-Bias was developed and applied in order to simulate the hysteresis and the first orde
Publicado em: 2008
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21. Estudo de rotas alternativas para a fabricação de ímãs compósitos à base de Sm2Fe17N3
This monograph thesis concerns the study of alternative processing routes regarding the fabrication of permanent magnets based on the Sm2Fe17N3 intermetallic compound. The study is mainly based on the compound synthesis in powder form and its subsequently shaping to get the final magnet body. Instead of the traditional induction melting of metallic samarium
Publicado em: 2008
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22. A study on the influence of titanium and cobalt ions in the magnetic and electromagnetic absorption properties of barium hexaferrite / Estudo da influência de íons titânio e cobalto nas propriedades magnéticas e absorvedoras de ondas eletromagnéticas de hexaferrita de bário / Estudo da influência de íons titânio e cobalto nas propriedades magnéticas e absorvedoras de ondas eletromagnéticas de hexaferrita de bário / A study on the influence of titanium and cobalt ions in the magnetic and electromagnetic absorption properties of barium hexaferrite
In this work Cobalt and Titanium doped Barium hexaferrites were synthesized by the ceramic method in order to study their use as electromagnetic absorbing materials in high frequencies. The dopants were used individually (Ti and Co) and with both simultaneously (CT). Ceramic characteristics and magnetic properties of calcined powders, as well as of their pel
Publicado em: 2008
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23. A study of high-energy milling for the production of sintered PrFeB magnets
Sintered Pr16Fe76B8 magnets have been produced using the hydrogen decrepitation (HD) process and high-energy planetary ball milling. Investigations have been carried out to evaluate the influence of the milling speed and time. The best magnetic properties obtained were Br = (1020 ± 20) mT, µ0iHc = (1420 ± 30) mT and (BH)max/= (200 ± 4) kJm-3, for a magne
Materials Research. Publicado em: 2007-09
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24. Characterization of the structural and magnetic properties of Nd16Co76-xRu xC7B alloys
The Nd16Co76-xRu xC7B system has been investigated to assess the effect of boron-carbon combined addition on the ferromagnetic behavior of these intermetallic compounds. The results indicate that the addition of 1 at.% B favors the formation of the tetragonal magnetic phase 2:14:1 in these alloys. With the increase of the Ru concentration is observed an expa
Brazilian Journal of Physics. Publicado em: 2007-09