Title :
Improved J/sub c/ property of Bi2223 tapes made using AgCu alloy-sheath doped with Ti, Zr, Hf or Au
Author :
Tanaka, Y. ; Matsumoto, F. ; Maeda, H. ; Ishizuka, M.
Author_Institution :
Nat. Res. Inst. for Metals, Tsukuba, Japan
fDate :
6/1/1995 12:00:00 AM
Abstract :
Bi2223 superconducting tapes have been prepared by the powder-in-tube technique using Ag-10at%Cu-xat%M (x=0-1.0, M=Ti, Zr, Hf or Au) alloy sheaths. The alloy-sheathed tape samples, prepared by repeating 2 or 3 times of sintering and cold pressing, showed high J/sub c/ values. The higher critical current densities, J/sub c/´s, 5-6/spl times/10/sup 4/A/cm/sup 2/, at 4.2 K, 14 T were obtained for the Ag-10at%Cu-(0.03-0.1at%Ti, 0.1at%Zr, 0.1at%Hf and 0.3at%Au) tape samples. Microstructural examinations of these samples revealed a modified Bi2223 grain structure at the sheath/core interface and also a denser and more aligned microstructure. X-ray diffraction analysis, vibrating sample magnetometer measurement and ac susceptibility studies seem to suggest an enhancement of the Bi2223 phase formation with high T/sub c/ and improved texture, resulting in higher J/sub c/.<>
Keywords :
X-ray diffraction; bismuth compounds; calcium compounds; copper alloys; critical current density (superconductivity); crystal microstructure; gold alloys; hafnium alloys; high-temperature superconductors; lead compounds; magnetic susceptibility; powder technology; silver alloys; sintering; strontium compounds; superconducting tapes; texture; titanium alloys; zirconium alloys; (BiPb)/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O-AgCuAu; (BiPb)/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O-AgCuHf; (BiPb)/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O-AgCuTi; (BiPb)/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O-AgCuZr; 14 T; 4.2 K; AC susceptibility; X-ray diffraction; alloy-sheathed tape; cold pressing; critical current density; grain structure; high temperature superconductor; microstructure; powder-in-tube technique; sintering; superconducting tapes; texture; vibrating sample magnetometry; Critical current density; Gold alloys; Hafnium; Magnetic analysis; Magnetic cores; Microstructure; Pressing; Superconducting films; X-ray diffraction; Zirconium;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
