Angular hysteresis in the critical current of YBa2Cu3O7 low-angle grain boundaries

• Published in: Superconductor science & technology Vol. 14; no. 9; pp. 647 - 650
• Main Authors: Hogg, Michael J, Kahlmann, Frank, Barber, Zoe H, Evetts, Jan E
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Bristol IOP Publishing 01.09.2001; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Critical currents; Cuprates superconductors (high tc and insulating parent compounds); Exact sciences and technology; High-Tc compounds; Physics; Properties of type I and type II superconductors; Superconductivity; Vortex lattices ,flux pinning, flux creep; Y-based cuprates; Grain boundaries; Critical current density; Inorganic compounds; Transition element compounds; Magnetic field effects; Experimental study; Flux pinning; Barium oxides; High-Tc superconductors; Quaternary compounds; Copper oxides; Hysteresis; Yttrium oxides
• ISSN: 0953-2048; 1361-6668
• DOI: 10.1088/0953-2048/14/9/301

The dependence of Jc on the orientation of an applied magnetic field has been measured for two YBa2Cu3O7 [001]-tilt low-angle grain boundaries. As the field is rotated in the boundary plane, a marked hysteresis in the variation of Jc with angle is observed. The effect is visible as a clear shift in the position of the intrinsic pinning peak as a function of the direction of field rotation (q+ or q-). Authors observe a switch over from Jc(q+) to Jc(q-) in a few degrees of field rotation and find angular hysteresis is increasingly pronounced at both low field and low temperature. Similar measurements taken on intragranular tracks displayed no hysteresis, suggesting the effect is associated with the presence of the grain boundary. Authors explore one possible model, involving flux trapping within the sample, to explain this hysteretic behavior. 11 refs.