THE INFLUENCE OF PRECURSOR VARIABLES ON THE PHASE FORMATION,MICROSTRUCTURE AND TRANSPORT PROPERTY OF Bi—2223／Ag TAPES

The Bi-2223/Ag tapes were prepared with spray-died powders, which are of differentparticle sizes and phase assemblages by varying the annealing time in pure oxygen.Longer time annealing degraded the reactivity of precursor powder, which in turnresulted in an incomplete conversion from precursors to Bi-2223, porosity core andmisaligned grains in fully processed tapes. The best Jc in short pressed samples variedfrom 29.7 to 47kA/cm2 for the tapes made from different powders.