0000000000007270
AUTHOR
Andres Sotelo
Ag/(Bi, Pb)-Sr-Ca-Cu-O superconducting tape processing: Solid state chemistry aspects
Abstract Different preparation methods have been used to obtain starting powders used in the fabrication of composite tapes by the powder-in-tube method. The effect of these distinct starting powders on the superconducting properties of Ag/Bi-Sr-Ca-Cu-O monofilament tapes has been investigated. The changes in the physical properties, including the critical current density at 77 K and ac magnetic susceptibility, and microstructure, using optical and electronic microscopy, have been analyzed in relation to the solid state reactions involved in the Bi 2 Sr 2 CaCu 2 O 8+δ and Bi 2 Sr 2 Ca 2 Cu 3 O 10+δ phase transformations.
Polymer solution processing of (Bi, Pb)SrCaCuO
Abstract A simple polymer processing route to the 110 K phase (Bi, Pb) 2 Sr 2 Ca 2 Cu 3 O 10+δ superconductor has been developed. The influence of the polymer to metal starting ratio, as well as the sintering temperature and time on the quality of the resulting superconducting powders has been studied by XRD, a.c. susceptibility and resistivity measurements. Microstructure of ceramic compacts has been studied by SEM, and qualitatively analysed by EDS for compositional homogeneity. The results indicate that the polymer synthesis route described here may offer a good alternative to the conventional solid state preparation methods towards attaining homogeneous 110 K superconductor powder withi…
(Bi,Pb)2Sr2Ca2Cu3O10+δ superconductor composites: Ceramics vs. fibers
Abstract Well characterized (Bi, Pb) 2 Sr 2 Ca 2 Cu 3 O 10+δ superconductor powder has been used to prepare superconductor-glass, -metal and -alloy composites through solid state reaction method. A recently developed Laser Floating Zone (LFZ) apparatus has been used to transform the ceramic precursors into oriented fibers. The diamagnetic properties have been studied by a.c. susceptibility. The microstructure of fibers has been studied by SEM and compared with that of the original ceramic precursors. XRD has been used to study phase composition on representative composite samples and fibers. The results indicate some potential for the 2223-Ag composite, which displays improved diamagnetic p…