Enhancement in J(c) of Bi-2212/Ag tapes

Highly textured Bi2Sr2Ca1Cu2O8+delta (Bi-2212) tapes were prepared on both sides of 50 mum thick Ag substrates in alternating electrolytic depositions and heat treatments. We have found that very small changes in stoichiometr y can affect the melting behaviour of the Bi-2212 matrix. the volume fracti on of the alkaline earth cuprates phases and consequently can influence the transport current density value of the tapes. Optimisation of the process has led to a significant reduction of the density of the secondary phases i n the bulk of the samples with a correlative dramatic increase in the J(c) value in self-field at 77 K up to 40 000 Angstrom cm(-2) in a reproducible way. (C) 2001 Elsevier Science B.V. All rights reserved.