Mechanisms of limitation and nature of field dependence of critical current in HTS epitaxial YBaCuO films

• Published in: IEEE transactions on applied superconductivity Vol. 13; no. 2; pp. 3714 - 3717
• Main Authors: Pan, V.M., Pashitskii, E.A., Ryabchenko, S.M., Komashko, V.A., Pan, A.V., Dou, S.X., Semenov, A.V., Tretiatchenko, C.G., Fedotov, Yu.V.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.06.2003; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Critical current; Critical current density; Current measurement; Density measurement; Electronics; Exact sciences and technology; High temperature superconductors; High-tc films; Magnetic field measurement; Magnetic films; Magnetic susceptibility; Microelectronic fabrication (materials and surfaces technology); Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Superconducting films and low-dimensional structures; Superconductivity; Temperature dependence; Yttrium barium copper oxide; Temperature distribution; Critical current density; Statistical distribution; Abrikosov vortices; Swirling flow; high-temperature superconductors; Epitaxial film; Critical field; Thin film; Magnetic susceptibility; edge dislocations; Crystalline material; Critical current; Direct current; Superconducting quantum interferometer device; Cathodic sputtering; epitaxial thin films; Curve fitting; Magnetic field; High temperature superconductor
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2003.812523

Magnetic field and temperature dependencies of the critical current density, J/sub c/(H/spl par/c, T) were measured by SQUID-magnetometry, ac magnetic susceptibility, and dc transport current techniques in the single-crystalline epitaxially-grown by off-axis dc magnetron sputtering YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO) films with J/sub c/(H/spl par/c, 77 K) /spl ges/ 2 /spl middot/ 10/sup 6/ A/cm/sup 2/. The mechanism of vortex depinning from growth-induced linear defects, i.e., out-of-plane edge dislocations in low-angle tilt domain boundaries, is shown to describe quantitatively measured J/sub c/(H/spl par/c, T). The developed model takes into account a statistical distribution of the dislocation domain boundaries ordered in a network as well as the interdislocation spacing within boundaries. Actual structural features of YBCO film known from HREM data turn out to be extracted from J/sub c/(H/spl par/c, T)-curves by a fitting procedure within the proposed model.