Abstract

The critical current density (Jc) of two epitaxial thin films of Y1Ba2Cu3O7−δ has been measured as a function of temperature in magnetic fields up to 27 T. A detailed study of one of the films shows that when the transport current is in the a-b plane and the magnetic field is orthogonal to the c axis, the functional form of Jc is consistent with both a polynomial (flux pinning) description and an exponential (pair breaking) description. In contrast, when the current is in the a-b plane and the applied field is parallel to the c axis of the film, Jc is unambiguously exponential of the form Jc=α(T)exp[−μ0H/β(T)]. These results explain why there are conflicting suggestions in the literature as to the mechanism that determines Jc in high magnetic fields in thin films for J⊥H⊥c axis and provide evidence that pair breaking operates for J⊥ H∥c axis. However, the standard phenomenological superconductor-normal-superconductor junction model derived in the clean limit for the normal metal cannot describe this pair-breaking mechanism.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.