Improved J/sub c/ property of Bi2223 tapes made using AgCu alloy-sheath doped with Ti, Zr, Hf or Au
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/.<<ETX>>