Superconducting wire and method of producing the same

摘要

This invention provides an oxide-type superconducting flat wire having a critical current density of at least 1,000 A/cm2, which comprises a Y-Ba-Cu oxide layer having a superconducting property and a silver layer surrounding the oxide layer and has so flat a cross section vertical to the longitudinal direction of the wire that the upper and lower lines between the oxide layer and the silver layers appearing on the cross section having a zone over they are parallel to each other, the thickness of the oxide layer being cold rolled in the range of 0.35 to 0.75 based on the whole thickness of the wire, the whole thickness being 0.2 mm or less, and the metal layer being deformable to follow the shrink deformation of the oxide layer when heat treated to be sintered, but rigid when used. This flat wire is produced by filling a silver-made tube with a Y-Ba-Cu oxide powder having a superconducting property, drawing the tube into a rod wire having a round cross section, then cold rolling the rod wire in the flat wire so that (ti-t)/tix100 is equal to or greater than 90%, wherein ti is the whole thickness of the cross section of the rod wire before the cold rolling and t is the whole thickness of the cold-rolled flat wire, and then heat treating the flat wire to sinter the superconducting oxide.