Abstract:
The effect of codoping of Pb and rare earths rare earths REs =La, Gd, and Yb in Bi-2212
superconductor on structural, transport, and flux pinning properties was investigated in comparison
with solo doping of REs. While the solo doping led to marked improvements in critical temperature
TC , critical current density JC , and in-field JC JC-B , the codoping exhibited very large
enhancements in JC and JC-B at a relatively high temperature of 64 K. Pb doping at Bi site improved
the coupling between the two dimensional pancake vortices and the strongly coupled vortices were
effectively pinned by the defects created at Sr/Ca sites by RE doping. © 2007 American Institute
of Physics.
