Hyperfine Fields
Mostrando 1-10 de 10 artigos, teses e dissertações.
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1. Theoretical studies of the EPR parameters for Ni2+ and Co+ in MgO
The electron paramagnetic resonance (EPR) parameters (g factors and the hyperfine structure constants) for Ni2+ and Co+ in MgO are theoretically studied from the perturbation formulas of these parameters for a 3d8 ion in octahedral crystal-fields. In the computations, the ligand orbital and spin-orbit coupling contributions are taken into account using the c
Brazilian Journal of Physics. Publicado em: 2010-09
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2. Local magnetic moments and hyperfine fields at Ta impurities diluted in XFe2 (X = Y, Gd, Yb) Laves phases compounds
Neste trabalho, estudamos, à temperatura finita, a sistemática na formação dos momentos locais de uma impureza de Ta diluída em compostos intermetálicos de fases de Laves XFe2 (X = Y, Gd, Yb). Utilizamos um hamiltoniano de Hubbard, extendido à duas sub-redes acopladas, para descrever as matrizes de fases de Laves. A interação eletrônica d-d é trat
Journal of the Brazilian Chemical Society. Publicado em: 2008
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3. Investigation of hyperfine interactions in pure silicon and NTD silicon by means of perturbed angular γ-γ correlation spectroscopy / Investigação de interações hiperfinas em silício puro e silício NTD pela técnica de correlação angular gama-gama perturbada
In the present work, a microscopic investigation of hyperfine interactions in single crystal silicon samples was carried out by means of Perturbed Angular γ-γ Correlation technique (PAC), which is based in hyperfine interactions. In order to achieve these measurements, it was used 111In ->111Cd radioactive probe nuclei, which decay through the we
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 22/02/2007
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4. Processos redoxes de ferro em argilominerais: caracterização, métodos de quantificação, especiação e modificações estruturais
Redox processes within clays and clay minerals influence significantly in different physical and chemical properties in soils and sediments, mainly which ones related to the chemical interaction between solid and solution phases (liquid or gas) such as superficial charge and ion dynamics. Other, like expansibility, water retention capacity, surface area, and
Publicado em: 2007
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5. Propriedades Magnéticas Locais de Grãos de Co em Cu e Ag / Local magnetic properties of Co grains in bulk Cu and Ag
A descoberta da magnetoresistência (GMR) em materiais granulares gerou um grande interesse no estudo destes materiais, havendo um empenho particular no estudo de grãos de CO em CU e AG. Como as propriedades de transporte estão ligadas intimamente às estruturais, o entendimento da GMR nestes materiais requer uma descrição acurada destas características
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/11/1999
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6. Estudo experimental de campos hiperfinos magnéticos em ligas de heusler
In the present work we report on the measurements of magnetic hyperfine fields (mhf), acting on 111 Cd as impurity in the series of Heusler alloys Pd2MnIn1 _ xSn x, Pd2MnSn1 _ ySby and Pd 1+x MnSb for values of x and y between O and 1, by using the differential perturbed angular correlation technique. The alloys of Pd2MnIni _ xSnx are antiferromagnetic for x
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 1979
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7. Medidas magneto-óticas de tempos de relaxação Spin-Rede em KBr e nos halogenetos de Na e Cs e estudo de Dicroismo Circular Magnético do Ion Co++ em KCl. / Magneto-optical measurements of spin-lattice relaxation times in KBr, Na and Cs halides and Magnetic Circular Dichroism of Co++ dopped KCl.
In this work we describe a Magnetic Circular Dicroism Spectrometer wich was used in the following experiments: 1) We measured the spin-lattice relaxation time (T1) for F centers in NaCl, NaBr, CsBr and CsCl, at 1,8°K in magnetic fields up to 15000Gs. We verified the suitability of the theory of ref.(O8) to explain the differences observed for halides of
Publicado em: 1977
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8. Estudo da interação hiperfina magnética nos núcleos de 207 Pb em ferro como função da temperatura
The presente work is composed of three parts. In the first we make a synthesis of the historical evolution and the present state of the magnetic hyperfine interaction studies, especially in dilute ferromagnetic alloys. In the second part we analyse the experimental method, discussing the fundamental ideas of angular correlation and comparing it to other tech
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 1972
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9. MÖSSBAUER SPECTROSCOPY OF THE IRON-SULFUR PROTEINS*
The Mössbauer spectra of 57Fe in two plant ferredoxins (from spinach and Euglena) and in xanthine oxidase have been measured at a series of temperatures and magnetic fields, and are found to be similar in all three proteins. In the oxidized state the iron is nonmagnetic. In the reduced state, the iron nuclei show magnetic hyperfine interaction with an elect
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10. Anisotropic magnetic interactions in the primary radical ion-pair of photosynthetic reaction centers
The quantum yield of triplets formed by ion-pair recombination in quinone-depleted photosynthetic reaction centers is found to depend on their orientation in a magnetic field. This new effect is expected to be a general property of radical pair reactions in the solid state. For 0 < H < 1,000 G, the quantum yield anisotropy is caused by anisotropic electron d