The comparable effects on transport properties in Bi2Sr2Ca1-xPrxCu2Oy and Bi2Sr2Ca1-xYxCu2Oy single crystals

The in-plane resistivity rho(ab)(T) of single crystals Bi2Sr2Ca1-xPrxCu2Oy (x ranging from 0 to 0.5) and Bi2Sr2Ca1-xYxCu2Oy (x ranging from 0 to 0.41) has been measured. The doping has dramatic effects on the two systems. In the Pr doped system, T-c is suppressed gradually upon doping while the resi dual resistivity increases strongly. A superconductor-insulator transition is observed when the Pr content reaches about 0.5. In the Y doped system, i t is found that rho(ab)(T) deviates from T-linear behavior at a characteris tic temperature T*, which is an evidence of a pseudogap. T* increases with the increase of Y doping. T-c is suppressed more rapidly in this system tha n in the Pr doped system. We suppose that a general correlation exists betw een anomalous Pr magnetism and a lack of pseudogap in the Pr doped system. (C) 2000 Elsevier Science B.V. All rights reserved.