Tc Superconductor
Mostrando 1-12 de 15 artigos, teses e dissertações.
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1. Fe-Doping Effect on the Bi3Ni Superconductor Microstructure
The substitution effects of Fe ion on the structure of the intermetallic Bi3Ni1-xFex (0 ≤ x ≤ 0.10) superconductor were studied. The morphology of samples consists of an inhomogeneous laminar slab-like microstructure. The main phase corresponds to Bi3Ni1-xFex with an orthorhombic structure (Pnma), but with very small quantities of impurities of BiNi and
Mat. Res.. Publicado em: 13/03/2017
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2. PROCESSAMENTO, CARACTERIZAÇÃO E ESTUDO DOS FENÔMENOS CRÍTICOS NO SUPERCONDUTOR (Gd1 xCex)Ba2Cu3O7- δ
This work presents a systematic study of the effects of CeO2 addition to the superconductor system (Gd1-xCex)Ba2Cu3O7δ, with 0,0 x 0,05, in polycrystalline form. Samples were obtained following the solid state reaction standard technique in which high purity chemical precursors (99,99%) were employed, Gd2O3, CeO2, BaCO3 and CuO. For the structural chara
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/03/2012
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3. PROCESSAMENTO, CARACTERIZAÇÃO E ESTUDO DE FENÔMENOS CRÍTICOS NOS SISTEMAS SUPERCONDUTORES (Er,Gd)1−xPrxBa2Cu3O7 / PROCESSAMENTO, CARACTERIZAÇÃO E ESTUDO DE FENÔMENOS CRÍTICOS NOS SISTEMAS SUPERCONDUTORES (Er,Gd)1−xPrxBa2Cu3O7
Neste trabalho foram estudados os efeitos das flutuações térmicas na condutividade elétrica de amostras policristalinas com base nos supercondutores Er1xPrxBa2Cu3O7 e Gd1xPrx Ba2Cu3O7. A quantidade de Pr considerada foi x = 0, 00, 0, 05 e 0, 10. As amostras foram preparadas pela técnica padrão de reação de estado sólido e caracterizadas por microsco
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/11/2010
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4. Study of the crystal structure of the high Tc superconductor Hg1-xRe xBa2Ca2Cu3O8+δ by using EXAFS, XANES and XRD
Hg based superconducting ceramics present the highest critical temperatures ever reported, particularly the phase 1223 with the highest Tc so far obtained -135 K. However, these compounds are obtained by a complex synthesis route and suffer degradation at ambient atmosphere. This disadvantage may be overcome by doping with an appropriate amount of Re. Sample
Materials Research. Publicado em: 2008-06
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5. Estudo do composto supercondutor Hg, Re-1223 por difratometria de raios-X, com a aplicação do método de Rietveld / STUDY OF THE SUPERCONDUCTING COMPOUND Hg,Re-1223 BY X-RAY DIFFRACTION WITH APLICATION OF RIETVELD METHOD
The objective of this work was to study the crystal structure of the superconductor compound of nominal composition Hg0,82Re0,18Ba2Ca2Cu3O8+ and general formula Hg,Re- 1223 and different oxygen contents, by the X-ray diffraction technique, by using the Rietveld method. The studied samples present different oxygen stoichiometry because during the synthesis pr
Publicado em: 2008
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6. ESTUDO DO PARÂMETRO DE ORDEM E DO MOMENTO MAGNÉTICO EM BOROCARBETOS PSEUDOQUATERNÁRIOS / STUDY OF ORDER PARAMETER AND MAGNETIC MOMENT IN PSEUDOQUATERNARY BOROCARBIDES
Experimental data show that the dissolved impurities of the Mn presents a magnetic moment when substitute the Ni atom in pseudoquaternary borocarbide Y (Ni(1−x)Mx)2B2C, this is not observed if the impurities are Fe and Co. In this work we do a theoretical study of the superconducting order parameter variation and a possible formation of impurities magn
Publicado em: 2007
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7. Pairing and coherence transition in La1.82Sr0.18CuO4 strongly two-dimensional superconductor
We report conductivity fluctuation measurements in the La1.82Sr0.18CuO4 high temperature superconducting material. The conductivity fluctuation analysis was performed by utilizing the concept of the logarithmic derivative of the conductivity excess. Close and above the critical temperature Tc, we experimentally determine the occurrence of Gaussian and critic
Brazilian Journal of Physics. Publicado em: 2006-09
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8. Quasiparticle energy spectrum and Josephson current in superconducting SNINS junctions
Through the solution of the Bogoliubov de Gennes equations we analyze the effect of different symmetries of the pair potential on the quasiparticle energy spectrum in SNINS junctions (S: superconductor, N: normal metal and I: Insulator). We find that the energy levels are strongly affected by the symmetry of the pair potential, the width of each normal metal
Brazilian Journal of Physics. Publicado em: 2006-09
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9. Distinguishing models for the pseudo-gap in cuprate superconductors by probing the spatial distribution of impurity states
We argue that the spatial distribution of resonant impurity states in underdoped high-Tc superconductors serves as a probe for distinguishing different theoretical models for the pseudogap state. Superconducting pairing fluctuations are characterized by off-diagonal short-range order which distinguishes them from other possible instabilities that could give
Brazilian Journal of Physics. Publicado em: 2003-12
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10. Development of (Nb,Ta)3Sn multifilamentary superconductor wire for high current applications
The optimization of the energy generated by a MagnetoHydroDynamic (MHD) channel using a superconducting magnet demands the optimization of the magnetic field of the system and of the critical points on the magnet winding. This work must include the development of a high performance superconductor wire suitable for this system. Aiming to the construction of i
Materials Research. Publicado em: 2000-10
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11. Single cristal growth of YBa2Cu3O7-ä superconductor the flux method using SnO2 crucibles. / Crescimento de monocristais supercondutores de YBa2Cu3O7-ä pelo método de fluxo em cadinhos de SnO2.
O método do fluxo tem se tornado uma das técnicas mais usadas, quando se trata de crescimento de monocristais supercondutores de YBa2Cu3O7-ä. A técnica processa o material no estado fundido e isto acarreta temperaturas nas quais reações podem acontecer. Na preparação de monocristais supercondutores da família Y-Ba-Cu-O, mais especificamente, YBa2Cu3
Publicado em: 1998
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12. Uso de metodo sol-gel e de coprecipitação na preparação de oxidos metalicos
This thesis describes the preparation of two crystalline solids obtained by thermal decomposition of poorly crystallized solids obtained by precipitation techniques. Magnetite a ferrimagnetic crystalline solid, was obtained by heating non-crystalline iron (III) hidroxoacetate (HAFe), under nitrogen. Mixed oxides of La-Ba-Cu and Y-Ba-Cu, which are superconduc
Publicado em: 1992