Microstructure and Electrical Properties of Bulk High-Tc Superconductors
Bulk forms of the superconductors Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O generally have a low critical current density (Jc). At 77 K in zero magnetic field, values greater than about 103 A cm−2 have seldom been obtained. The most notable exceptions are for melt-textured rods and filaments,1–3 for which Jc values often exceed 104 A cm−2. Values of Jc approaching 104 A cm−2 have also been reported for wires and tapes processed in Ag tubes.4–6 Little information about the microstructures of these composite conductors has emerged. This work was undertaken to examine the relationships between processing, microstructure, and electrical properties for high-temperature superconductors processed as pellets or Ag-clad tapes.
KeywordsCritical Current Density Bulk Form Zero Magnetic Field High Green Densi YBCO Powder
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