The comprehensive ρ(T) measurements and the consequent resistivity curvature mapping (RCM) on Y0.7Ca0.3Ba2Cu 3O7-δ thin films (doping levels p = 0.08-0.21) elucidate a phase diagram for the whole doping range. This phase diagram further strengthens a view that the 'normal' phase in hole-doped cuprates should be divided into a strong superconducting (SC) fluctuation phase and the 'real' normal phase in which there is no significant influence of SC. The temperature of superconducting fluctuations Tf as a function of p was calculated using the Ginzburg-Landau model for layered superconductors. Comparisons between Tf and the Nernst temperature establish the origin of the Nernst effect as SC fluctuations. Some of the details in ρ(T) cannot be fully understood by the existing models and call for a more sophisticated theory of carrier dynamics in cuprates.
|期刊||Superconductor Science and Technology|
|出版狀態||Published - 1 10月 2013|