Transport in the superconducting mixed state ofBi2+xSr2−yCuO6±δ

Abstract
Flux-flow resistance and Hall effect were measured in a Bi2+x Sr2y CuO6±δ crystal in the superconducting mixed state. The Hall mobility saturates to a temperature-independent plateau at μH=0.9 mT1 at high field (H>5 T), while the resistance varies nearly as log(H). The absence of features to identify Hc2(T) is contrasted with other type-II superconductors of similarly low Tc=7 K.