Composite Bi-2212/Ag superconductors grown by laser travelling floating zone at low rates

Abstract

Well-textured Bi2.02Sr2.02Ca0.98Cu1.99Ox/2.9 wt % Ag composite samples have been grown by the laser floating zone at very low rates (1, 3, and 5 mm/h). The as-grown samples present superconducting behavior, as a result of being composed by long and well-textured Bi-2212 grains as major phase. After annealing, the samples do not dramatically increase their JC. This effect has been associated with the presence of long cracks along the ab planes of the superconducting grains. Even after annealing, the cracks have not been totally removed and, as a consequence, the critical current of the samples after the thermal treatment has only been improved in around 50 %, compared with the as-grown samples.