Superconducting layer thickness of relaxation properties of persistent current in high magnetic field in YBCO-coated conductor

• Published in: Physica. C, Superconductivity Superconductivity, 2009-10, Vol.469 (15), p.1122-1125
• Main Authors: Matsutani, F., Himeki, K., Kiuchi, M., Otabe, E.S., Matsushita, T., Miyata, S., Ibi, A., Yamada, Y., Shiohara, Y.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Flux creep-flow model; formula omitted; Physics; Properties of type I and type II superconductors; Relaxation; Superconductivity; Thickness; Vortex lattices ,flux pinning, flux creep; YBCO
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/j.physc.2009.05.238

It was previously shown that the apparent pinning potential U 0 ∗ associated with the relaxation of superconducting current at low magnetic fields depended on the thickness of superconducting layer for IBAD/PLD-processed YBCO-coated conductors. It is necessary to clarify the thickness dependence of the relaxation property at high magnetic fields for application of YBCO-coated conductors in a persistent current mode at such magnetic fields. In this study, the thickness dependence was investigated in the field range of 1–6 T at 20 K for IBAD/PLD-processed YBCO-coated conductors with the superconducting layer thicknesses of 0.25 – 1.0 μ m . It was found that U 0 ∗ decreases monotonically with decreasing thickness at 6 T. This seems to be attributed to the two-dimensional pinning mechanism because of the longitudinal flux bundle size limited by the film thickness.