Sm-Ba-Cu-O bulk superconductors melt-processed in air

Recent development shows that melt-processed YBaCuO (Y123) and light rare-earth (LRE) BaCuO superconductors have a high J(c) at 77 K and high magnetic field. Solidification processes for producing RE 123 superconductors are effective for obtaining high J(c) and are very promising for high field application as a superconducting permanent magnet with the liquid nitrogen refrigeration. LRE BaCuO bulk superconductors melt-processed in a reduced oxygen atmosphere, named oxygen-controlled-melt-growth process. have a high T-c and J(c). However, processing in air is preferable for practical applications. In this study, we discuss Sm123 bulks melt-processed in air. and their characteristic superconducting properties. Isothermal undercooling growth in air with oxygen annealing and Nd123/MgO thin film cold seeding technique were applied in Sm1.8Ba2.4Cu3.4Oy/Ag system to seek the high efficiency of process, homogeneity of composition, and feasibility of batch production. Single-domain growth was achieved using this technique. The result implies that melt-processed in air applying isothermal method and thin film seeding in Sm system is fit for producing larger bulks in large scale applications. (C) 2002 Elsevier Science B.V. All rights reserved.