Microstructures and superconducting properties of Ag alloy sheathed Bi-2223 tapes
- Sumitomo Heavy Industries, Ltd., Hiratsuka (Japan)
- National Institute for Research in Inorganic Materials, Namiki, Tsukuba (Japan)
- National Institute for Research in Inorganic Materials, Namiki, Tsukuba (Japan); and others
Bi-2223 superconducting tapes were prepared by the powder-in-tube technique using Ag-10 at%Cu-x at%M (M=Ti, Zr or Hf, X=0 - 1.0) alloy sheaths. The alloy sheathed tapes with a very small amount doping of Ti, Zr or Hf, the doped tapes, exhibited considerably higher J{sub c} values than those of pure Ag or Ag-10 at%Cu sheathed tapes, the non-doped tapes. The highest J{sub c} values at 4.2 K/14 T and 77 K/0.4 T reached around 9.0x and 1.0x10{sup 4} A/cm{sup 2}, respectively, for the doped tapes, especially for the 0.1 - 0.03 at%Ti or 0.1 at% Hf doping. Compared with the non-doped tapes, the doped tapes show in most case larger magnetic moment. SEM microstructures observed on the core surfaces of these tapes revealed large flat-shaped Bi-2223 grains containing neither subgrains nor small stick-shaped grains. Furthermore, high resolution transmission electron microscopy revealed that amorphous disc-like regions with less than 5 nm in thickness parallel to (001) plane were introduced into Bi-2223 lattice in parallel to CuO{sub 2} layer. These changes in grain morphology and existence of amorphous disc-like regions may strongly be related to the high J{sub c}, properties of the doped tapes, especially the amorphous regions may play the important role as one of pinning centers.
- OSTI ID:
- 482056
- Report Number(s):
- CONF-950722--
- Journal Information:
- Advances in Cryogenic Engineering, Journal Name: Advances in Cryogenic Engineering Vol. 42B; ISSN 0065-2482; ISSN ACYEAC
- Country of Publication:
- United States
- Language:
- English
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