DoMayn-orientation dependence and low anisotropy factor of levitation force in top-seeded melt-textured bulk YBCO

Forschungszentrum Karlsruhe GmbH, INFP, P.O. Box 3640, 76021 Karlsruhe, Germany

Corresponding author: axel.Kaiser2@de.bosch.com

Received: 5 October 1998
Revised: 15 February 1999
Accepted: 15 February 1999
Published online: 15 June 1999

Abstract

Bulk Y₁Ba₂Cu₃O_y was melt-textured without the use of seed crystals as well as by applying top-seeding with different seeds resulting in different orientations of the c-axis. Samples were examined by elastic neutron scattering and levitation force. The levitation force of the samples strongly depends on the orientation of the c-axis. The local superconducting parameters were found to be reduced with increasing distance from the seed. In order to study this influence, two cubes were prepared by top-seeding, but with seeds of Nd123 that had a parallel and perpendicular orientation of the c-axis of the Nd123-seed with respect to the contact area of the high-T_c superconductor. By this, different distances of the levitating surface, which is the surface that faces directly the magnet, from the seed were obtained. Results are presented and discussed.