Resistivity study of the pseudogap phase for (Hg,Re)-1223 superconductors

Abstract

The pseudogap phase above the critical temperature of high- Tc superconductors (HTSC) presents different energy scales and it is currently a matter of intense study. The complexity of the HTSC normal state requires very accurate measurements with the purpose of distinguishing different types of phenomena. Here we have performed systematically studies through electrical resistivity (ρ) measurements by several different current densities in order to obtain an optimal current for each sample. This approach allows us to determine reliable values of the pseudogap temperature T* (n), the layer coupling temperature between the superconductor layers TLD (n), the fluctuation temperature Tscf (n), and the critical temperature Tc (n) as a function of the doping n. The interpretation of these different scales allows us to characterize possible scenarios for the (Hg,Re)-1223 normal state. This method, described in detail here, and used to derive the (Hg,Re)-1223 phase diagram is general and can be applied to any HTSC. © 2006 The American Physical Society.