WEAK LINKS AND FLUX-PINNING IN AG BIPBSRCACUO TAPES

Weak links and pinning properties of Ag-sheathed (Bi,Pb)2Sr2Ca2Cu3O10y (2223) wires have been investigated through measurements of the tran sport and magnetisation J(c) and of the irreversibility lines (IL). Th e IL for both the tape and the scraped powder from the tape are nearly equally shifted to higher temperatures in comparison with that for th e normal powder, suggesting that the enhanced IL is attributable to in tragrain pinning. Results on the transport and magnetisation J(c) of t hese tapes suggest that the critical current is controlled by flux pin ning. Grain boundary weak links are largely reduced for high quality t apes at high temperatures, while the weak link behaviour becomes prono unced at low temperatures.