In this study, we measured the magnetization of GdBa2Cu3O7-δ(GdBCO) coated conductors in
the perpendicular external magnetic field by using the Magnetic Property Measurement System for various geometries of ring-shaped specimens which have different number and width of narrow paths respectively. We patterned specimens by direct maskless lithography with the UV-laser scanning system. The magnetization curve was measured at the temperature corresponding to the same ratio of the measured the irreversible temperature 𝑇𝑖𝑟𝑟 to each patterned specimen. We focused on magnetic hysteresis losses of specimens which have different geometries. The model for the superconducting narrow rings and Bean’s critical state model were used to analyze experimental results. According to our investigation, the full penetration field 𝐻𝑝 of each specimen is determined by the number and width of narrow paths. When the superconducting rings have narrow paths, its partial full penetra- tion field is lower than a ring specimen by the Ampere's law. For this reason, supercon- ducting rings which have narrow paths have totally lower full penetration field and its hysteresis loss is lower than a ring specimen because of narrow paths. In conclusion, it was confirmed that the characteristics of the superconducting rings dominantly varied depending on the number and width of narrow paths. To find the exact effect of narrow paths for the distribution of current density, we have to carry out the local magnetization measurement for further study.
Thesis Advisor: Prof. Hyeong-Cheol Ri