Abstract
Bi2.2-xPbxSr2Ca2.2Cu3Oy silver sheathed((Bi, Pb)-2223/Ag) tapes with different Pb doping amounts, x = 0.4, 0.5,0.6, are prepared by the powder-in-tube method. X-ray diffraction analysesmanifest that the tape with x = 0.5 has more Pb-rich phase than that of a tape withx = 0.4. For the tape with x = 0.6, there is a large amount ofCa2PbO4 phase and a small amount of Pb-rich phase. Scanning electronmicroscopy and transmission electron microscopy observations show that thePb-rich phase with nanometre order of magnitude is embedded in the(Bi, Pb)-2223 grain matrix of samples. The magnetic field dependence ofthe critical current density of the tape with x = 0.5 is noticeablyimproved at 77 K, and its irreversibility line is also shifted to highertemperatures and magnetic fields in comparison with the tape with x = 0.4,which is usually considered as the standard Pb doping level in preparing(Bi, Pb)-2223/Ag tapes. The resistivity measurement of the normal statereveals that the anisotropy of the tape with x = 0.5 is also decreasedcompared with the tape with x = 0.4. The enhanced flux pinning seems tomainly originate from the fine Pb-rich phase particles themselves and theextra defects induced by the larger Pb-rich phase particles.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call