Magnetic field dependence of the resistivity and susceptibility of the above-100-K Bi-Sr-Ca-Cu superconductor

The magnetic field dependence of the resistivity and susceptibility of multiphase Bi-Sr-Ca-Cu-O compounds exhibiting transport and diamagnetic anomalies at ≃115 and ≃75 K are reported. The field dependence of the latter yields values of $H_{c1\mathrm{}}$ and $d\frac{H_{c2\mathrm{}}}{\mathrm{dT}}(T=T_c)$ very similar to those found for the $\mathrm{Y}\mathrm{}\left(R\right)\mathrm{}{\mathrm{Ba}}_2{\mathrm{Cu}}_3{\mathrm{O}}_{7-x}$ family of Cu perovskitelike superconductors. The field dependence of the above-100-K region strongly suggests that bulk superconductivity, as opposed to filamentary or fluctuation behavior, dominates at these temperatures.