SIGN REVERSAL OF THE HALL RESISTIVITY OF SINGLE-CRYSTALLINE BI(1.95)SR(1.65)LA(0.4)CUO(6+DELTA)AND BI2SR2CACU2O8+DELTA

摘要

The Hall effect of single-crystalline Bi2Sr2CaCu2O8+delta and Bi1.95Sr1.65La0.4CUO6+delta has been measured above and below the superconducting transition temperature T-c0 by applying magnetic fields H parallel to c and currents I perpendicular to c, where c denotes the direction perpendicular to the Cu-O planes of these materials. For both compounds, the Hall resistivity rho(xy)(T,H) reveals similar temperature and field dependences. As T approaches T-c0 from higher temperatures, the rho(xy)(T,H) versus H curves gradually deviate from linearity and exhibit an unusual sign reversal in the low-field regime. The total Hall resistivity rho(xy)(T,H) may be decomposed into three distinctly different terms, i.e., rho(xy)(T,H)= rho(xy)(0)(T)+R(H)(1)(T). H+rho(xy)(x)(T,H). The contribution rho(xy)(x)(T,H), representing the deviation of rho(xy)(T,H) from H linearity, exhibits a universal scaling behavior as a function of H/H-0(T) for fields between 0 and H-0(T), the field below which rho(xy)(T,H) is no longer linear in H. [References: 29]