High-magnetic-field study of superconductingYBa2Cu3O7−δ

The resistance of single-phase samples of $\mathrm{Y}{\mathrm{Ba}}_2{\mathrm{Cu}}_3{\mathrm{O}}_{7-\delta }$ has been measured as a function of temperature in magnetic fields up to 23 T. The nearly linear temperature dependence of the resistivity characteristic of this high-$T_c$ material was observed from room temperature down to about 120 K. Between 120 K and $T_{c0\mathrm{}}\sim 92.5$ K the resistivity drops more quickly. Analysis shows this behavior to be consistent with the effect of three-dimensional superconducting fluctuations as was shown by Tsuei et al. for zero magnetic field. A critical-field slope of 3.2 T/K is obtained.