Enhancement of critical current density of (Pb,Sn)-doped Bi-2212 superconductors at high temperature
Author
Li, Y.
Kaviraj, S.
Berenov, A.
Perkins, G.K.
Driscoll, J.
Caplin, A.D.
Cao, G.H.
Ma, Q.Z.
Wang, B.
Wei, L.
Zhao, Z.X.
Attention
2299/11698
Abstract
The magnetic properties of ceramic samples of Bi(PbSn)SrCaCu O (x = 0,0.1,0.2,0.3 and 0.4) superconductors have been investigated using a vibrating sample magnetometer from 20 to 50 K and up to 8 T. Phase analysis shows that most of the (Pb,Sn) dopant enters the Bi-2212 lattice and occupies Bi sites. The current-carrying scale-length analysis has been determined from the reverse leg of the magnetization hysteresis loops and compared to the actual dimensions of the sample. Magnetization hysteresis loops of the (PbSn)-doped sample exhibit strong pinning behaviour in the higher temperature range. The effect of (Pb,Sn) doping on intragranular critical current J was found to be enhanced by one order of magnitude at 50 K. We discuss the experimental results within a model of (PbSn) cluster pinning in blocking layers. Doping by (PbSn) clusters into the Bi-O layers provides effective pinning centres, as well as a large reduction of the resistivity anisotropy.