SCALING BEHAVIOR FOR RESISTANCE TRANSITION IN Hg-1223 SUPERCONDUCTOR UNDER PRESSURE

Abstract

The effects of high pressure on the temperature dependence of the resistance transition of Hg -1223 superconductor are measured up to 7.8 GPa. At a pressure lower than 5.4 GPa, Tc increases from 130 K to a maximal value of 140 K with a rate of 1.85 K/GPa. At higher pressure, Tc begins to decrease. This pressure dependence of critical temperature can be explained with the sheet charge model, which introduces the inhomogeneous charge distribution in the inner and outer CuO 2 layer(s). The temperature dependence of the resistance under various pressure can be scaled onto a single curve with P=0ρ(T)=Pρ(aT), where the scaling parameter a is estimated to be smaller than 1. Further, the scaling parameter a reflects the relative change of the anisotropy factor γ.