Show simple item record

dc.contributor.authorVieira, Valdemar das Nevespt_BR
dc.contributor.authorSchaf, Jacobpt_BR
dc.date.accessioned2014-09-30T02:12:34Zpt_BR
dc.date.issued2002pt_BR
dc.identifier.issn1098-0121pt_BR
dc.identifier.urihttp://hdl.handle.net/10183/103926pt_BR
dc.description.abstractVery 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) single crystals are reported. The irreversibility lines Tirr(H) of the pure single crystal show a considerable planar anisotropy but follow the same power-law regime, for both field orientations, arising within the conventional flux-creep theories in the whole field range. Very differently, however, the Tirr(H) lines of the doped superconductors exhibit besides large anisotropies, several different regimes. In fields lower than 8 kOe the Tirr(H) data of the doped samples display the de Almeida–Thouless (AT) and Gabay-Toulouse (GT)-like power-law behaviors, the signature of a frustrated superconductor. For higher-field values, and in particular for H||c, flux dynamics seems to be conventional. However, for H||ab and field values above 30 kOe, the flux dynamics displays sharp directional properties along the twinning planes (TP’s) for rotations about the c axis. This behavior is cusplike, comparable to that caused by columnar defects, which characterizes a Bose-flux-glass phase. We appoint the superconducting granularity and frustration as responsible for the AT and GT behaviors below 8 kOe and the strong anisotropic pinning for H parallel to the TP’s as the cause of the Bose-glass features. On the other hand, the isotropic pinning for large angular displacements or for any angle in fields below 30 kOe is the most probable cause of the vortex-glass features.en
dc.format.mimetypeapplication/pdf
dc.language.isoengpt_BR
dc.relation.ispartofPhysical review. B, Condensed matter and materials physics. Vol. 65, no. 14 (Apr. 2002), 144531, 9 p.pt_BR
dc.rightsOpen Accessen
dc.subjectCompostos de báriopt_BR
dc.subjectAprisionamento de fluxopt_BR
dc.subjectSupercondutores de alta temperaturapt_BR
dc.subjectEfeito josephsonpt_BR
dc.subjectCompostos de estrônciopt_BR
dc.subjectCompostos de ítriopt_BR
dc.titleAnisotropic 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 featurespt_BR
dc.typeArtigo de periódicopt_BR
dc.identifier.nrb000314037pt_BR
dc.type.originEstrangeiropt_BR


Files in this item

Thumbnail
   

This item is licensed under a Creative Commons License

Show simple item record