LRE-BA₂cu₃o_y superconductors on the way to applications

The current status, recent development and production techniques for bulk LRE-BA₂cu₃o_y"LRE-123" (LRE=light rare earth, Nd, Eu, Sm, Gd, NEG, SEG) superconductorsare presented. The emphasis is focused on the flux pinning of LRE-123materials, especially the size effect of the initially added nanometer-sized Gd-211, thenew class of nano-scale pinning centers contaminated by a minute amount of Zr-, Ti-,Mo- or Nb- oxides. The topic is reviewed and discussed especially from the viewpoint ofapplications of superconducting permanent magnets in a variety of industrial applicationsincluding Maglev technology. For this aim, a batch process has been developed allowingfabrication of a large quantity of single-domain LRE-123 bulks melt-textured in air or inAr/1% O2 atmosphere, using a cold seeding method with Nd-123/MgO films. Using thesebatch-processed LRE-123 bulks, a child levitation disk, a child Maglev vehicle etc. havebeen constructed that proved that the present technology is capable of producingsuperconducting materials with a reasonable cost and high performance suitable fordesign of powerful superconducting super-magnets.