Figure 3. Determination of magnetic and superconducting transition temperatures from the resistivity curves under high pressure.

(a–f) Temperature dependence of resistivity ρ(T) (left axis) and temperature derivative of resistivity dρ/dT(T) (right axis) at low temperatures. The temperature at the maximum slope of superconducting transition is defined as and the zero resistivity temperature as T_c. The magnetic transition temperature T_m is determined by the dip or peak in dρ/dT(T). At 6.3 GPa, the data at 9 T is also shown where T_m anomaly appears when the superconducting transition is suppressed to a lower temperature (e). At 8.8 GPa, the normal-state resistivity can be fitted to a T-linear dependence (dashed line in (f)).