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| HAL : hal-00464075, version 1 |
| DOI : 10.1103/PhysRevB.81.174517 |
| Fiche détaillée |  Récupérer au format |
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| Physical Review B 81 (2010) 174517 |
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| Flux pinning in PrFeAsO0.9 and NdFeAsO0.9F0.1 superconducting crystals |
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Cornelis Van Der Beek 1Giancarlo Rizza 1 |
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| (01/05/2010) |
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| Local magnetic measurements are used to quantitatively characterize heterogeneity and flux line pinning in PrFeAsO_1-y and NdFeAs(O,F) superconducting single crystals. In spite of spatial fluctuations of the critical current density on the macroscopic scale, it is shown that the major contribution comes from collective pinning of vortex lines by microscopic defects by the mean-free path fluctuation mechanism. The defect density extracted from experiment corresponds to the dopant atom density, which means that dopant atoms play an important role both in vortex pinning and in quasiparticle scattering. In the studied underdoped PrFeAsO_1-y and NdFeAs(O,F) crystals, there is a background of strong pinning, which we attribute to spatial variations of the dopant atom density on the scale of a few dozen to one hundred nm. These variations do not go beyond 5 % - we therefore do not find any evidence for coexistence of the superconducting and the antiferromagnetic phase. The critical current density in sub-T fields is characterized by the presence of a peak effect, the location of which in the (B,T)--plane is consistent with an order-disorder transition of the vortex lattice. |
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| 1 : | Laboratoire des Solides Irradiés (LSI) |
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CNRS : UMR7642 – CEA : DSM/DRECAM – Polytechnique - X |
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| 2 : | Synchrotron SOLEIL (SSOLEIL) |
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CNRS : UR1 |
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| 3 : | Centre de Recherche sur les Ions, les Matériaux, et la Photonique (CIMAP) |
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CNRS : UMR6252 |
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| 4 : | Institut Néel |
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CNRS : UPR5031 |
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| 5 : | Department of Physics, Kyoto University |
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Kyoto University |
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| 6 : | Quantum Beam Science Directorate (QUBS) |
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Japan Atomic Energy Agency |
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| 7 : | Nanoelectronics Research Institute (NeRI) |
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National Institute of Advanced Industrial Science and Technology AIST |
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| 8 : | Department of Physics and Astronomy, Iowa State University |
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Iowa State University |
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| Domaine | : | Physique/Matière Condensée/Supraconductivité |
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| Iron pnictide superconductors – flux pinning – critical current – flux creep – vortex phase diagram – disorder |
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| Liste des fichiers attachés à ce document : | ||||||||||
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| hal-00464075, version 1 | |
| http://hal.archives-ouvertes.fr/hal-00464075 | |
| oai:hal.archives-ouvertes.fr:hal-00464075 | |
| Contributeur : Cornelis Jacominus Van Der Beek | |
| Soumis le : Lundi 15 Mars 2010, 18:37:38 | |
| Dernière modification le : Jeudi 20 Mai 2010, 08:13:01 | |
