Hyperfine Magnetic Field
Mostrando 1-12 de 21 artigos, teses e dissertações.
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1. The Structural and the Magnetic Properties of Aluminum Substituted Yttrium Iron Garnet
In this paper, Y3AlxFe5-xO12 powders with x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0 were prepared via solid state reaction method. X-ray diffraction, Vibrating Sample Magnetometry, and Mössbauer Spectroscopy were used to study their structural and magnetic properties. The XRD patterns of the samples show single phase structure with decreasing lattice constant wh
Mat. Res.. Publicado em: 15/03/2018
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2. Electronic Effect of V, Ti, and Sc Impurities on the Hyperfine Interactions of Fe Atoms in α-Fe: A First Principles Study
The Linearized Augmented Plane Wave method, as implemented in the Wien2k computational code, was used to investigate the effects of the 3d transition metals (TM) Sc, Ti, and V impurities on the hyperfine interaction of iron atoms in α-Fe. The calculation results of this study suggest that the introduction of a TM (TM = Sc, Ti, and V) impurity into α-Fe inc
Mat. Res.. Publicado em: 02/03/2017
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3. Estudo da Estrutura Local dos SÃtios de Ferro em Ligas FeCrMo por Espectroscopia MÃssbauer e DifraÃÃo de Raios -X / Study of the local structure of iron sites in Fe-Cr-Mo alloys by MÃssbauer Spectroscopy and X-ray Diffraction
Ligas Fe-Cr-Mo sÃo amplamente utilizadas na fabricaÃÃo de tubulaÃÃes para a indÃstria petroquÃmica nos processos de transporte e refino do petrÃleo devido a uma combinaÃÃo de propriedades como dureza, tenacidade e resistÃncia à fluÃncia e à corrosÃo em altas temperaturas. Atualmente, a liga Fe-9Cr-1Mo à a mais comumente utilizada. Contudo, em
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/06/2011
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4. A first-principles study of Cr impurities in iron
The first-principles molecular cluster discrete variational method (DV) is used to investigate the electronic structure and local magnetic properties of Cr impurities in bcc iron and Fe/Cr interfaces. The spin polarized case is considered within the framework of the local-spin-density approximation of the density function theory. The effect on the local mome
Brazilian Journal of Physics. Publicado em: 2006-12
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5. Spin dynamics of electrons and holes in p-doped InAs/GaAs quantum dots
We have investigated the electron and hole spin dynamics in p-doped semiconductor InAs/GaAs quantum dots by time resolved photoluminescence. We observe a decay of the average electron spin polarisation down to 1/3 of its initial value with a characteristic time of TD » 500ps. We attribute this decay to the hyperfine interaction of t
Brazilian Journal of Physics. Publicado em: 2006-06
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6. Desenvolvimento de um detector de alta eficiência para espectroscopia Mossbauer de elétrons de conversão (CEMS) a baixas temperaturas (<20 K) e testes em bicamadas Fe/ (EUxPb1-x)Te / Development of a highly efficient conversion electron Mossbauer spectroscopy (CEMS) detector for low temperature (<20 K) measurements and tests on Fe/ (EuxPb1-x)Te bylayers
The 57Fe Mössbauer spectroscopy is a nuclear, non-destructive technique used for the investigation of structural, magnetic and hyperfine properties of several materials. It is a powerful tool in characterizing materials in physics, metallurgy, geology and biology field areas, especially magnetic materials, alloys and minerals containing Fe. Lately, the Conv
Publicado em: 2006
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7. Implantation of 111In in the Heusler alloys Pd2MnZ (Z=Sn,Sb,Ge,In) following heavy ion nuclear reactions: measurement of magnetic hyperfine field using PAC spectroscopy
Ion implantation of the recoil 111In nuclei following heavy ion nuclear reactions 108Pd(7Li,4n)111In and 108Pd(6Li,3n)111In has been used to implant 111In probes in the Heusler alloys Pd2MnZ(Z=Sn,Sb,Ge,In). Perturbed Angular Correlation method was used to study the hyperfine magnetic field in these alloys. Direct implantation of 111In probe nuclei was used t
Brazilian Journal of Physics. Publicado em: 2005-09
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8. Estudo de taxas de perdas em sistemas heteronucleares / Trap loss in a two-species Rb-Cs magneto-optical trap
In this work, we had investigated the heteronuclear trap loss rate in a two-species Rb-Cs magneto-optical trap. The experimental results suggest that radiative escape is the main collisional process responsible for heteronuclear losses. An addapted Gallagher - Pritchard model is compared with the data. The model is very sensitive to the trap depth, which dep
Publicado em: 2001
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9. Estudos dos momentos magneticos em solidos por ressonancia paramagnetica eletronica
Electron Paramagnetic Resonance (EPR) of magnetic impurities (3d e 4f) in single crystals and powdered samples is a subject of importance in the study of magnetic impurities in solids. The study and analysis of the EPR spectra is the main subject of this work. We developed computational algoritms to simulate and fit EPR spectra, using a suitable Spin Hamilto
Publicado em: 2000
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10. Construction of and auto-balanced ac suceptometer and study of eletronic conductor polymers for magnetic susceptibility and magnetic resonance. / Construção de um Susceptômetro AC Autobalanceado e Estudo de Polímeros Condutores Eletrônicos por Susceptibilidade Magnética e Ressonância Magnética.
A mutual inductance bridge which may be used for automatic measurement of ac magnetic susceptibilities from 4 K to room temperature, at frequencies up to 1 kHz, is described. The susceptometer employs an alternative and new arrangement for the probe. The coil set is kept at room temperature and moves in such a way to place the sample in the center of each of
Publicado em: 1998
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11. Espectroscopia não-linear de alta resolução em I2, Ti e Ar+
In this work we performed nonlinear high-resolution spectroscopy in I2, Ti and Ar+. Iodine was used as a wavelength reference in the visible. Doppler limited spectra of this molecule were obtained, in particular by using photoacoustic detection. This one proved to be comparable to detection with photodetectors in terms of sensibility and signal-to-noise rati
Publicado em: 1994
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12. Medidas de tempos de relaxação spin-rede em cristais mistos de halogenetos alcalinos. / Spin-lattice relaxation measurements on mixed crystals of alkali halides.
Using magneto-optic techniques we have studied the ground state spin- lattice relaxation times (T1) of Fcenters in mixed Alkali Halide cristals (KCl-KBr). We describe a computer assisted system to optically measure short relaxation times (~1mS). The technique is based on the measurement of the Magnetic Circular Dicroism (MCD) presented by F centers. We obtai
Publicado em: 1983