Influence of Multiple Angled Columnar Defects on Critical Current Density and n–Value in YBCO Thin Films

• Published in: Physics procedia Vol. 36; pp. 1570 - 1575
• Main Authors: Sueyoshi, Tetsuro, Nishimura, Takahiro, Fujiyoshi, Takanori, Mitsugi, Fumiaki, Ikegami, Tomoaki, Ishikawa, Norito
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2012
• Subjects: Critical current density; Crossed columnar defects; Flux creep; Critical current density; Flux creep; Crossed columnar defects
• ISSN: 1875-3892; 1875-3892
• DOI: 10.1016/j.phpro.2012.06.212

To investigate the influence of multiple angled columnar defects (CDs) on flux pinning properties, three controlled splay configurations of CDs were installed by heavy–ion irradiation in YBCO thin films: a parallel configuration of CDs, bimodal splay configurations consisting of crossed CDs at ±10° or ±45° relative to c–axis, and a trimodal one consisting of crossed CDs at 0° and ±45°. The critical current density Jc for the trimodal configuration is higher than those of any other configuration for all magnetic fields. In particular, the n–value for the trimodal configuration is remarkably enhanced and exhibits a shoulder behavior for lower magnetic fields below the matching field Bφ