Title :
Enhanced flux pinning through a phase formation-decomposition-recovery process in Ag-sheathed Bi(Pb)SrCaCuO wires
Author :
Dou, S.X. ; Liu, H.K. ; Guo, Y.C. ; Shi, D.L.
Author_Institution :
Sch. of Mater. Sci. & Eng., New South Wales Univ., Kensington, NSW, Australia
fDate :
3/1/1993 12:00:00 AM
Abstract :
A high-critical temperature, T/sub c/, phase formation-decomposition-recovery (PFDR) process has been developed for fabrication of Ag-sheathed (Bi,Pb)/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10+y/ (2223) wires with a short period of melt during the heat treatment. A critical current density, J/sub c/, of 40000 A/cm/sup 2/ at 77 K and 0 T and of 9000 A/cm/sup 2/ at 77 K and 1 T has been achieved. The irreversibility line for the PFDR tape is shifted to much higher temperature than those for normal tape and powder sample for fields up to 6 T. The PFDR processed samples contain a large amount of small spheres of Sr- and Ca-rich phase with a diameter of 1 mu m to 3 mu m, well aligned 2223 grains, highly dispersed, textured 2212 and high concentrations of dislocations (10/sup 10//cm/sup 2/) and stacking faults. The strong coupling between grains is attributed to the interfacial pinning.<>
Keywords :
bismuth compounds; calcium compounds; ceramics; critical current density (superconductivity); decomposition; flux pinning; heat treatment; high-temperature superconductors; lead compounds; magnetic field effects; powder technology; recovery; silicon; stacking faults; strontium compounds; 6 T; Ag-(BiPb)/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10+y/; Ag-sheathed Bi(Pb)SrCaCuO wires; HTSC; critical current density; dislocations; fabrication; flux pinning; heat treatment; high-critical temperature; interfacial pinning; magnetic field; phase formation-decomposition-recovery process; powder; stacking faults; texture; Fabrication; Flux pinning; Heat engines; Heat treatment; Laboratories; Magnetization; Materials science and technology; Powders; Temperature; Wires;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
