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

Bulk Y1Ba2Cu3Oy was melt-textured without the use of seed crystals as well as by applying top-seeding with different seeds resulting in different orie ntations 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 wer e found to be reduced with increasing distance from the seed. In order to s tudy 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 o f the Nd123-seed with respect to the contact area of the high-T-c supercond uctor. By this, different distances of the levitating surface, which is the surface that faces directly the magnet, from the seed were obtained. Resul ts are presented and discussed.