Fabrication of textured YBCO bulks with artificial holes

摘要

The recently reported hole-patterned YBa2Cu3Oy (Y 123) bulks with improved superconducting properties are highly interesting from the aspects of the material qualities and application various points of view. It is well known that the core of plain bulk superconductors needs to be fully oxygenated and some defects like cracks, pores and voids must be suppressed in order that the material can trap high magnetic field or carry high current densities. To minimize the above defects, we have used the infiltration and top seed growth (ITSG) process to prepare regularly perforated YBa2Cu3Oy (Y123) bulk superconductors. This process involves less shrinkage during annealing and a uniform distribution of Y211 inclusions. The texture was evidenced by neutron pole figure measurements. Flux mapping was used to verify the superconducting homogeneity of the samples and to investigate the field trapping ability. Large increase of the trapped field in pulsed magnetization up to 60% in comparison to the hole-free parent sample with the same thermal history has been obtained. In addition, the textured drilled samples were reinforced using resin or metal impregnation and the influence of the different processing steps on the hardness of the materials is investigated. (C) 2007 Elsevier B.V. All rights reserved.