Listar Ciencias Exactas y Naturales por tema "Compostos de bário"
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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) [Artículo 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) ... -
Co-cubstitution effects on the Fe valence in the BaFe2As2 superconducting compound : a study of hard x-ray absorption spectroscopy
(2011) [Artículo de periódico]The Fe K x-ray absorption near edge structure of BaFe₂-xCoxAs₂ superconductors was investigated. No appreciable alteration in shape or energy position of this edge was observed with Co substitution. This result provides ... -
Effects of Ca and Sr chemical doping on the average superconducting kinetic energy of YBa2Cu3O7-δ
(2015) [Artículo de periódico]In this brief communication we applied the MZFC(T) and MFCC(T) reversible dc magnetizations to get the average superconducting kinetic energy density, kS(T,B) of YBa2Cu3O7-d, Y0.95Ca0.05Ba2Cu3O7-d and YBa1.75Sr0.25Cu3O7-d ... -
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) [Artículo 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 ... -
Influence of impurities on the luminescence of Er3+ doped BaTiO3 nanophosphors
(2014) [Artículo de periódico]The influence of the presence of barium carbonate (BaCO3) phase on the luminescence properties of barium titanate nanocrystals (BaTiO3) powders was investigated. Structural and optical characterizations of erbium (Er3+) ... -
Irreversibility limits of the Abrikosov and Josephson flux dynamics in homogeneous and granular high-T/sub c/ superconductors
(2001) [Artículo 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 ... -
Pairing transition, coherence transition, and the irreversibility line in granular GdBa/sub 2/Cu/sub 3/O/sub 7-[delta]/
(2000) [Artículo 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 ... -
Pressure and chemical substitution effects in the local atomic structure of BaFe2As2
(2011) [Artículo de periódico]The effects of K and Co substitutions and quasihydrostatic applied pressure (P < 9 GPa) in the local atomic structure of BaFe2As2, Ba(Fe0.937Co0.063)2As2 and Ba0.85K0.15Fe2As2 superconductors were investigated by extended ... -
Unconventional superconducting granularity of the Y/sub 1-x/Pr/sub x/Ba/sub 2/Cu/sub 3/O/sub 7-[delta]/ compound
(2006) [Artículo 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 ...