Navegação por Assunto "Supercondutores de alta temperatura"
Resultados 1-9 de 9
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Anisotropic irreversibility of the Abrikosov and Josephson flux dynamics in YBa/sub 2-x/Sr/sub x/Cu/sub 3/O/sub 7-[delta]/ single crystals : Bose-glass and vortex-glass features
(2002) [Artigo de periódico]Very detailed magnetic irreversibility data for fields applied along the c axis or the ab plane of a pure and untwinned YBa₂Cu₃O₇₋₈ single crystal and Sr-doped and heavily twinned YBa₂₋xSrxCu₃O₇₋₈ (x=0.25, 0.37, and 0.5) ... -
Efeitos de pressão nas flutuações termodinâmicas da condutividade elétrica de supercondutores de alta temperatura crítica
(2004) [Tese]O presente trabalho consiste de um estudo experimental dos efeitos de pressão externa sobre as flutuações termodinâmicas da condutividade elétrica de supercondutores de alta temperatura crítica (HTSC). Para tanto, medidas ... -
Fases de stripes nos cupratos : um estudo do modelo t-J anisotrópico
(2003) [Dissertação]Neste trabalho realizamos um estudo de um buraco em um antiferromagneto, como parte de uma revisão de diferentes técnicas de abordagem das fases de “stripes” nos cupratos supercondutores. Estudamos a transição do formalismo ... -
Fluctuation magnetoconductivity in YBa/sub 2/Cu/sub 3/O/sub 7/ : Gaussian, three-dimensional XY, beyond three-dimensional XY, and lowest-Landau-level scaling
(2001) [Artigo de periódico]Systematic measurements of the in-plane fluctuation magnetoconductivity in a YBa₂Cu₃O₇ single crystal are presented. Fields between 0 and 14 T were applied either parallel or perpendicular to the Cu-O atomic planes. The ... -
Irreversibility limits of the Abrikosov and Josephson flux dynamics in homogeneous and granular high-T/sub c/ superconductors
(2001) [Artigo de periódico]The magnetic irreversibility of a high-quality YBa₂Cu₃O₇₋₈ single crystal and of the granular superconductors YBa₁.₅Sr₀.₅Cu₃O₇₋₈ and YBa₁.₇₅Sr₀.₂₅Cu₃O₇₋₈ single crystals and the polycrystalline YBa₁.₇₅Sr₀.₂₅Cu₃O₇₋₈ sample ... -
Magnetic and orbital ordering of RuO/sub 2/ planes in RuSr/sub 2/ (Eu,Gd) Cu/sub 2/O/sub 8/
(2004) [Artigo de periódico]We start from an effective Hamiltonian for Ru ions in a square lattice, which includes the on-site interactions between t2g orbitals derived from Coulomb repulsion, and a tetragonal crystal-field splitting. Using perturbation ... -
Pairing transition, coherence transition, and the irreversibility line in granular GdBa/sub 2/Cu/sub 3/O/sub 7-[delta]/
(2000) [Artigo de periódico]We report on electrical magnetoconductivity experiments near the superconducting transition of a granular sample of GdBa₂Cu₃O₇₋₈. The measurements were performed in magnetic fields ranging from 0 to 500 Oe applied parallel ... -
Separated suppression of the transverse and longitudinal Josephson flux mobility in a Bi/sub 1.6/Pb/sub 0.4/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub y/ superconductor
(2001) [Artigo de periódico]We report on very detailed zero-field-cooling and field-cooling magnetization and magnetoresistance measurements in a polycrystalline Bi₁.₆Pb₀.₄Sr₂Ca₂Cu₃Oy superconductor. The results allow us to study the irreversibility ... -
Unconventional superconducting granularity of the Y/sub 1-x/Pr/sub x/Ba/sub 2/Cu/sub 3/O/sub 7-[delta]/ compound
(2006) [Artigo de periódico]We report on fluctuation magnetoconductivity and magnetic irreversibility of Y1−xPrxBa2Cu3O7− single crystals and a polycrystalline sample. Although our samples are all single phase orthorhombic and the single crystals ...