Effect of Ag-sheath doping on structure and properties of Bi-ceramic-basedcomposites

The effect of doping of silver sheaths with additions of (Ni + Y) and (Zr Al) on the structure and mechanical and superconducting characteristics of ribbon-like 2223 phase-based composites has been investigated. It has been shown that the observed strengthening of the alloyed silver sheaths and co mposites as a whole results from dopant-based oxide particles precipitation and grain structure refinement of the sheaths. It has been found that Ag-s heath doping affects structure and superconducting properties of ceramic co res. The fraction of high-temperature superconducting 2223 phase has been f ound to decrease, Critical current density has been shown to become somewha t lower, but its stability to thermal cycling in the temperature interval o f 77-293 K has been found to increase. (C) 1999 Elsevier Science B.V. All r ights reserved.