Fig. 1
From: Percolative nature of the direct-current paraconductivity in cuprate superconductors
a Temperature dependence of the dc resistivity of a Hg1201 single crystal with characteristic temperatures Tc ≈ 80 K (defined here to correspond to the lowest measurable nonzero resistivity), T** ≈ 140 K (defined as the deviation from low-temperature quadratic behavior), and T* ≈ 260 K (defined as the deviation from high-temperature linear behavior). b DC resistivity plotted versus the square of temperature and fit to ρ = ρ0 + aT2 between 100 K and 140 K (dashed line), which demonstrates Fermi-liquid behavior below T** and a very small residual resistivity in the zero-temperature limit (see text). The inset shows the residuals obtained upon subtracting the fit result from the data for fits between 100 K and 140 K (line) and 110 K and 130 K (symbols). The T2 behavior prevails over a ~40-K range. c Normalized VSM magnetization measurements, obtained with an external field of 15 Oe applied perpendicular to CuO2 planes. Solid circles: zero-field-cooled (ZFC) data; open circles: field-cooled (FC) data. These data demonstrate a well-defined superconducting transition at Tc ≈ 80 K and weak vortex pinning, indicative of a low level of point disorder
