Title :
Effect of post annealing on superconducting properties and microstructures of Bi(2212)/Ag tapes
Author :
Nagata, A. ; Yamauchi, S. ; Kamada, S. ; Sugawara, K. ; Takahashi, C. ; Nagano, M. ; Wakiya, Y. ; Hanada, S.
Author_Institution :
Min. Coll., Akita Univ., Japan
fDate :
6/1/1995 12:00:00 AM
Abstract :
Bi(2212)/Ag tapes were fabricated by the melt-growth method at various cooling rates in air and Bi atmosphere followed by furnace cooling. Post-annealing at 810/spl deg/C was carried out for improving T/sub c/ and J/sub c/. T/sub c/ of as-solidified tapes was /spl sim/80 K, which increased to /spl sim/90 K after post-annealing. J/sub c/ of as-solidified tapes was scattered even at the same fabrication condition. Post-annealing reduced scattering of J/sub c/ and improved J/sub c/ of the tape with lower J/sub c/ values. However, samples with high J/sub c/ (4.2 K, 0 T) of 6/spl times/10/sup 4/ A/cm/sup 2/ after solidification was little improved by post-annealing.<>
Keywords :
annealing; bismuth compounds; calcium compounds; cooling; critical current density (superconductivity); crystal microstructure; high-temperature superconductors; powder technology; silver; solidification; strontium compounds; superconducting tapes; superconducting transition temperature; 4.2 K; 80 K; 810 C; 90 K; Bi atmosphere; Bi(2212)/Ag tapes; Bi/sub 2/Sr/sub 2/CaCu/sub 2/O-Ag; air; cooling rates; critical current density; furnace cooling; high temperature superconductors; melt-growth method; microstructures; post annealing; solidification; superconducting properties; superconducting transition temperature; Annealing; Atmosphere; Bismuth; Cooling; Fabrication; Furnaces; Microstructure; Powders; Superconducting films; X-ray scattering;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
