Superconducting and mechanical properties of Sm-Ba-Cu-O bulk superconductors

Melt-processed REBaCuO (RE: rare-earth) superconductors have a high J(c) at 77 K and high magnetic field, and light rare-earth (LRE) BaCuO has a larger J(c) than Y123 in high magnetic field. These materials are expected to be applied to high field applications such as a superconducting permanent magnet with the liquid nitrogen refrigeration, flywheels, current leads, and so on. In this study, we discuss SmBaCuO bulks melt-processed in air and their characteristic superconducting and mechanical properties. Isothermal undercooling growth in air with oxygen annealing and Nd123/MgO thin film cold seeding technique were applied in SmBaCuO/Ag system to seek the high efficiency of process, homogeneity of composition, and feasibility of batch production. Single-domain growth of superconducting phases of a square larger than 15 mm. on a side and 10 mm in thickness was achieved using this technique. The result implies that melt-processed in air applying isothermal method and thin film seeding in Sm system is feasible for producing larger bulks in large scale applications. (C) 2004 Published by Elsevier B.V.