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Critical current density: Measurements vs. reality

Journal Article


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Abstract


  • Different experimental techniques are employed to evaluate the critical current density (Jc), namely transport current measurements and two different magnetisation measurements forming quasi-equilibrium and dynamic critical states. Our technique-dependent results for superconducting YBa 2Cu3O7 (YBCO) film and MgB2 bulk samples show an extremely high sensitivity of Jc and associated interpretations, such as irreversibility fields and Kramer plots, which lose meaning without a universal approach. We propose such approach for YBCO films based on their unique pinning features. This approach allows us to accurately recalculate the magnetic-field-dependent Jc obtained by any technique into the Jc behaviour, which would have been measured by any other method without performing the corresponding experiments. We also discovered low-frequency-dependent phenomena, governing flux dynamics, but contradicting the considered ones in the literature. The understanding of these phenomena, relevant to applications with moving superconductors, can clarify their dramatic impact on the electric-field criterion through flux diffusivity and corresponding measurements. © Copyright EPLA, 2013.

Authors


  •   Pan, Alexey
  •   Golovchanskiy, Igor A. (external author)
  •   Fedoseev, Sergey (external author)

Publication Date


  • 2013

Citation


  • Pan, A. V., Golovchanskiy, I. A. & Fedoseev, S. A. (2013). Critical current density: Measurements vs. reality. Europhysics Letters: a letters journal exploring the frontiers of physics, 103 (1), 17006-1-17006-5.

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=2302&context=eispapers

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/1293

Start Page


  • 17006-1

End Page


  • 17006-5

Volume


  • 103

Issue


  • 1

Abstract


  • Different experimental techniques are employed to evaluate the critical current density (Jc), namely transport current measurements and two different magnetisation measurements forming quasi-equilibrium and dynamic critical states. Our technique-dependent results for superconducting YBa 2Cu3O7 (YBCO) film and MgB2 bulk samples show an extremely high sensitivity of Jc and associated interpretations, such as irreversibility fields and Kramer plots, which lose meaning without a universal approach. We propose such approach for YBCO films based on their unique pinning features. This approach allows us to accurately recalculate the magnetic-field-dependent Jc obtained by any technique into the Jc behaviour, which would have been measured by any other method without performing the corresponding experiments. We also discovered low-frequency-dependent phenomena, governing flux dynamics, but contradicting the considered ones in the literature. The understanding of these phenomena, relevant to applications with moving superconductors, can clarify their dramatic impact on the electric-field criterion through flux diffusivity and corresponding measurements. © Copyright EPLA, 2013.

Authors


  •   Pan, Alexey
  •   Golovchanskiy, Igor A. (external author)
  •   Fedoseev, Sergey (external author)

Publication Date


  • 2013

Citation


  • Pan, A. V., Golovchanskiy, I. A. & Fedoseev, S. A. (2013). Critical current density: Measurements vs. reality. Europhysics Letters: a letters journal exploring the frontiers of physics, 103 (1), 17006-1-17006-5.

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=2302&context=eispapers

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/1293

Start Page


  • 17006-1

End Page


  • 17006-5

Volume


  • 103

Issue


  • 1