Hysteresis Loops
Mostrando 13-24 de 33 artigos, teses e dissertações.
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13. 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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14. Structural and magnetic properties of the half-ferromagnetic Co2+x+yMn1-xAl1-y alloys
Co2+x+yMn1-xAl1-y intermetallic compounds have been prepared by arc melting and studied with X-ray diffraction and magnetization measurements to ascertain the effect of deviations of composition from the stoichiometry on the ferromagnetism of this system. Hysteresis loops registered at room temperature show a soft ferromagnetic behavior in excess Co. In off-
Brazilian Journal of Physics. Publicado em: 2007-12
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15. CRESCIMENTO, ESTRUTURA E POLARIZAÇÃO DE TROCA EM BICAMADAS FERROMAGNETO / ANTIFERROMAGNETO PREPARADAS POR DEPOSIÇÃO EM CONDIÇÕES DE EPITAXIA POR FEIXE MOLECULAR: Fe / EuTe(111), Fe / Ni50Mn50(001) e Ni1-xFex / Fe50Mn50
Magnetic interaction at interfaces between different layered magnetic materials is an important current topic in physics and materials science, particularly when combining ferromagnetic metals and semiconductors. The exchange bias effect associated with the exchange coupling between antiferromagnetic (AFM) and ferromagnetic (FM) systems, has been extensively
Publicado em: 2007
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16. Box model for hysteresis loops of arrays of Ni nanowires
In the present work, by means of a phenomenological model, we simulate the hysteresis loop of an hexagonal array of Ni nanowires. Our model is based on the assumption that the hysteresis loop of a single wire is a rectangular box with a particular value of the coercive field, and the effect of the array is to generate a distribution of the coercive fields. O
Brazilian Journal of Physics. Publicado em: 2006-09
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17. A new current transformer model
This paper presents a current transformer model that is useful on low frequency applications. To describe the iron core magnetic behaviour of the iron core, a hysteresis model is proposed, which is able to generate minor asymmetric loops and remanent flux. The effects of classic eddy current losses and anomalous losses are represented by linear and nonlinear
Sba: Controle & Automação Sociedade Brasileira de Automatica. Publicado em: 2005-09
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18. Desenvolvimento de um microscópio óptico e magnetoóptico de varredura em campo-próximo / Development of a Magneto-optical Scanning Near-field Optical Microscope (MO-SNOM)
To support nanosciences evolution, there is a strong demand for developing new instrumentation devoted to nano-scale characterization. In this context, the development of the Scanning Near-field Optical Microscope (SNOM) took place. In contrast to traditional optical microscopes, SNOM deals with evanescent electromagnetic radiation and, consequently, the res
Publicado em: 2005
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19. Preparação e caracterização de catalisadores de níquel suportado em óxido de zircônio e aluminio.
Alumina-supported nickel has been extensively used to catalyze the methane steam reforming because of its low cost, as compared to noble metal-based catalysts. However, it is not stable during the reaction mainly due to phase transition and sinterization. This calls for the development of new catalysts. An attractive option would be the use of zirconia-based
Publicado em: 2005
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20. O magnetometro a Efeito Kerr e o filme fino de Co/Si
The aim of this work was to study and implement a technique for the characterization of the magnetic properties of thin films through a Kerr magnetometer (MEK). First we present the phenomenology behind the magneto-optic Kerr effect. In the sequence we present the magnetometer (MEK) and the experimental procedures applied to get hysteresis loops from the mag
Publicado em: 2002
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21. Efeito Kerr magneto-óptico espectral e sperimagnetismo de filmes amorfos de terra rara-Co / Spectral magneto-optical Kerr effect and magnetism-speri of the films of amorphous rare earth-Co
We have observed the spectral behavior of the transverse magnetooptical Kerr effect (TMOKE) in thin films of rare earth - cobalt amorphous alloys for the visible and the near-ultraviolet ranges of spectrurn (wavelength fiom 325 nm up to 670 nm). The relative change of reflectivity has shown a maximum at the blue wavelength. We have concluded that this magnet
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/05/2001
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22. Processos de magnetização em supercondutores do tipo II : um estudo em monocristal de ErBaCuO com defeitos colunares
We present in this work a study of the magnetization and vortex lattice behavior, when a superconducting ErBa2CU3O7-d single crystal with columnar defects is rotated under a fixed magnetic field. We describe the procedures used in the development of BaZrO3 crucibles, and in the growth of YBa2CU3O7-d and ErBa2CU3O7-d single crystals using this crucible and al
Publicado em: 2001
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23. ELASTIC-PLASTIC HYSTERESIS LOOPS INDUCED BY COMPLEX LOADING / LAÇOS DE HISTERESE ELASTOPLÁSTICOS GERADOS SOB CARREGAMENTO COMPLEXOS
The main objective of this work was to experimentally study the cyclic elastoplastic behavior under complex leading of two structural steels, named API S-135 and AISI 4340. In order to minimize experimental errors, some problems were studied with unusual care. The influence of the residual bending moment on the EN tests was measured, using a special specimen
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 17/01/2000
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24. Hysteresis effects of C1H4 and C2H4 in the regions of the solid-phase transitions
The thermodynamic model of hysteresis in phase transitions based on the regular solution theory, previously developed, was applied to the solid phases of C1H4 and C2H4. The width and height of the hysteresis loops for these systems were calculated and compared with the experimental data; agreement was satisfactory.