The effect of nanometer Ca2PbO4 precipitates on flux pinning in Bi-2223/Agtapes

For the purpose of introducing extra flux pinning centers, nanometer Ca2PbO 4 precipitates were produced in (Bi,Pb)(2)Sr2Ca2Cu3Ox silver-sheathed tapes by means of post-annealing the fabricated tapes in flowing oxygen. The nor malized critical current density of the post-annealed samples is much highe r than that of non-annealed samples under a magnetic field up to 1T. XRD an d SEM analysis show that nanometer Ca2PbO4 precipitates appear during annea ling. These fine Ca2PbO4 precipitates may be responsible for the enhanced f lux pinning for (Bi,Pb)-2223/Ag tapes. (C) 2000 Elsevier Science B.V. All r ights reserved.