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Title: Irreversibility line in superconductor as line of constant shielding current density

The irreversibility of magnetic properties of superconductors is due to the existence of macroscopic shielding currents persisting for some period of time. The same currents offer nearly lossless electricity transport. Thus, the extent of magnetic irreversibility is directly proportional to the current-carrying capacity of a superconductor. Because the current-carrying capacity is an intrinsic property of the material, various experimental techniques should give the same irreversibility line corresponding to the same macroscopic shielding current density. Following this approach, the authors compared the irreversibility lines obtained from AC susceptibility measurement with those determined from quasistatic magnetization loops recorded with the help of a SQUID susceptometer. An additional parameter which has to be comparable is the electrical field characterizing the rate of change of the magnetic field. Fulfilling these conditions of equivalency, the authors found that it is possible to explain the irreversibility lines obtained by various techniques and at different conditions by the same physical model. They demonstrate that for the data, taken within two orders of magnitude for the current density and more than seven orders of magnitude for the electrical field, a consistent picture expressing all the observed features by the same model can be found. Measurements are presented frommore » YBCO samples.« less
Authors:
;  [1] ;  [2]
  1. Institute of Electrical Engineering, Bratislava (Slovakia)
  2. Technical Univ. Vienna (Austria) [and others
Publication Date:
OSTI Identifier:
482060
Report Number(s):
CONF-950722--
Journal ID: ACYEAC; ISSN 0065-2482; CNN: Contract GAV 2/1087/1994;Contract OWP-35; TRN: 97:001732-0010
Resource Type:
Journal Article
Resource Relation:
Journal Name: Advances in Cryogenic Engineering; Journal Volume: 42B; Conference: CEC/ICMC `95: cryogenic engineering conference and international cryogenic materials conference, Columbus, OH (United States), 17-21 Jul 1995; Other Information: PBD: 1997
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COPPER OXIDES; ELECTRIC CONDUCTIVITY; YTTRIUM OXIDES; BARIUM OXIDES; HIGH-TC SUPERCONDUCTORS