Flux Pinning Properties of Bi,Pb2223 Films With Columnar Defects by Xe Irradiation

• Published in: IEEE transactions on applied superconductivity 2018-06, Vol.28 (4), p.1-4
• Main Authors: Fujiyoshi, T., Sueyoshi, T., Kuwahara, R., Sakai, S., Matsumoto, A., Kitaguchi, H., Ishikawa, N.
• Format: Article
• Language: English
• Subjects: columnar defects; critical current density; Degradation; flux pinning; High temperature superconductors superconducting films; Ions; Magnetic fields; Magnetic films; Radiation effects; Sputtering
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2018.2807809

High-quality Hfand Zr-doped Bi,Pb2223 films on SrTiO 3 substrate were fabricated by RF magnetron sputtering and two-step annealing. In order to investigate flux pinning properties of columnar defects, Xe-ions were irradiated onto the Hfand Zr-doped Bi,Pb2223 films along the c-axis. Although the critical temperature T c was decreased by heavy ions irradiation, the infield critical current density J c in the magnetic field parallel to the c-axis was increased drastically. The enhancement of Jc was achieved in a wide range of magnetic fields over the matching magnetic field B φ . In the angular dependence of J c , the improvement of J c was observed in almost all angle region of magnetic field orientation except for the vicinity of the ab-plane. However, the peak centered at the c-axis did not appear in the angular dependence of J c . This behavior was quite different from REBa 2 Cu 3 O y films installed columnar defects. The angular dependences of J c in the Hfand Zr-doped Bi,Pb2223 films were determined by the magnetic field component along the c-axis. These results are originated from the strong two-dimensional nature of the Bi,Pb2223 film.