Effect of grain-alignment on the levitation force of melt-processed YBCO bulk superconductors

Single-domain YBCO bulk superconductors have been fabricated by Top Seeded Melt Slow Cooling Growth (TSSCG) process. Two typical YBCO cylinder samples with differential grain-alignment were selected for the investigation of t he relationship between the grain-alignment and the levitation force under the same testing condition at liquid nitrogen temperature. It is found that the levitation force values is much different for the two samples, the lev itation force of the sample with H//c-axis is more than two times higher th an that of the samples with H perpendicular to c-axis. So it is necessary t o take account of this anisotropy in practical applications. The relationsh ip between a magnet and a superconductor can be well described with a doubl e exponential function. All the results are discussed in details.