Hyperfine Field
Mostrando 1-12 de 33 artigos, teses e dissertações.
-
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
-
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
-
3. Facile Method to Tune the Particle Size and Thermal Stability of Magnetite Nanoparticles
Nucleation and growth mechanism of iron oxide nanoparticles on zeolite template and their stability dependence are reported. Hyperfine field resulting from the variation of particle size indicates the effect of zeolite on particles growth; particle size decreases at lower concentration of zeolite. At higher concentration, a fraction of nano Fe3O4 experiences
J. Braz. Chem. Soc.. Publicado em: 2015-11
-
4. 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
-
5. Ab Initio calculations of interactions betweeen Cd and nitrogenous bases o DNA / Cálculos ab initio de interações entre Cd e bases nitrogenadas do DNA
As interações hiperfinas são uma ótima ferramenta para estudar um sítio específico e obter informações importantes sobre o sistema. No presente trabalho analisamos de forma teórica as propriedades eletrônicas, estruturais e hiper nas do Cádmio (Cd) ligado às bases nitrogenadas do DNA. A motivação surgiu da colaboração com o grupo do prof. Art
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 11/05/2011
-
6. Controlled reduction of LaFe xMn yMo zO3/Al2O3 composites to produce highly dispersed and stable Fe0 catalysts: a Mössbauer investigation
In this work, controlled reduction of perovskites supported on Al2O3 was used to prepare thermally stable nanodispersed iron catalysts based on Fe0/La2O3/Al2O3. The perovskites composites LaFe0.90Mn0.08Mo0.02O3(25, 33 and 50 wt (%)) /Al2O3 and LaFe0.90Mn0.1O3(25 wt (%)) /Al2O3 were prepared and characterized by XRD, BET, TPR, SEM and Mössbauer spectroscopy.
Materials Research. Publicado em: 2008-06
-
7. Eletronic estructure and hyperfine field of cobalt and nickel-related complexes in diamond / Estrutura eletrônica e campo hiperfino de impurezas complexas de cobalto e de níquel em diamante
As várias possibilidades de aplicações tecnológicas que o diamante permite, na indústria de dispositivos, impulsionaram os avanços de fabricação de amostras de diamante sintético de alta qualidade. O cristal de diamante crescido, do grafite, pela técnica de alta pressão e alta temperatura (HPHT - High Pressure-High Temperature), utiliza ligas de m
Publicado em: 2008
-
8. Estudos estruturais de histatina-5 e seu análogo, TOAC0-histatina-5: interação com metais e sistemas biomiméticos / Structural studies of Histatin-5 and its analogue, TOAC0-Histatin-5: interaction with metals and biomimetic systems
The mechanism of action of histatin-5 (Hst-5), an antifungal antimicrobial peptide from human saliva is not completely clarified. Circular dichroism (CD), fluorescence, and electron paramagnetic resonance (EPR) were used to examine the conformational behavior of Hst-5 and its analogue containing the paramagnetic amino acid TOAC at the N-terminus (TOAC0-Hst-5
Publicado em: 2008
-
9. 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
-
10. 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
-
11. 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
-
12. 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