Study on resistivity anisotropy and flux pinning of Bi2-xPbxSr2CaCu2Oy single crystals

摘要

Bi2-xPbxSr2CaCu2Oy ((Bi,Pb)-2212) single crystals with a large doping range up to x = 0.8 have been grown by the conventional self-flux method. The resistivity anisotropy of (Bi,Pb)-2212 single crystals and their transport properties under applied magnetic fields with Hparallel toc have been systematically studied. In-plane resistivity (rho(ab)), out-plane resistivity (rho(c)) and anisotropy (gamma) of (Bi,Pb)-2212 are significantly reduced by heavy Pb doping. The dissipation behavior of (Bi,Pb)2212 single crystals in the mixed state can be well described by the thermally activated flux creep model and flux creep is obviously suppressed for heavily Pb-doped single crystals. The origin of the improved flux pinning is suggested to stem mainly from the reduced anisotropy and the improved coupling strength between Cu-O layers due to Pb-doping. (C) 2002 Elsevier Science B.V. All rights reserved. [References: 15]