Angular Behavior of J(c) in GdBCO-Coated Conductors With Crossed Columnar Defects Around ab Plane

作者：Sueyoshi Tetsuro^*; Iwanaga Yasuya; Fujioyoshi Takanori; Takai Yohsuke; Mukaida Masashi; Kudo Masaki; Yasuda Kazuhiro; Ishikawa Norito

来源：IEEE Transactions on Applied Superconductivity, 2017, 27(4): 8001305.

DOI：10.1109/TASC.2016.2637338

• High-T-c superconductors
• critical current
• anisotropy
• flux pinning
• ion irradiation
• columnar defects

We investigated in detail the flux pinning properties around B parallel to ab for GdBCO-coated conductors with crossed colum-nar defects produced by heavy-ion irradiation, where the crossing angle Theta(i) was systematically controlled in the range from +/- 5 degrees to +/- 15 degrees relative to the ab plane. A single peak of critical current den-sity J(c) centered at B parallel to ab occurs for the crossing angle of Theta(i) = +/- 5 degrees, where an upward shift in J(c) can be observed compared to an unirradiated sample. As the crossing angle is larger, the J(c) peak becomes smaller and broader while maintaining the peak at B parallel to ab. Increasing Theta(i) up to +/- 15 degrees, three J(c) peaks emerges at B parallel to ab and at the two irradiation angles, independently from the others. The crossover behavior from the single peak to the triple one around the ab plane is attributed to the strong line tension energy of flux lines around B parallel to ab, which derives from the elliptical nature of the core of flux lines in anisotropic superconductors.

• 出版日期2017-6