Study of the Two-Gap Superconductivity in GdO(F)FeAs by ScS-Andreev Spectroscopy

文献摘要

Current-voltage characteristics and dynamic conductance of the superconductor constriction - superconductor junctions in GdO(F)FeAs polycrystalline samples with critical temperatures Tc^local = 46 - 53 K were investigated. Two superconducting gaps, the large Delta_L = 10.5 \pm 2 meV, and the small one Delta_S = 2.3 \pm 0.4 meV were clearly observed at T = 4.2 K. The 2Delta_L/kTc^local = 5.5 \pm 1 ratio gives support to the strong coupling mechanism which is responsible for the high Tc value. Temperature dependence of the large gap Delta_L(T) indicates the presence of intrinsic proximity effect (in k-space) between two superconducting condensates.

Current-voltage characteristics and dynamic conductance of the superconductor

constriction - superconductor junctions in GdO(F)FeAs polycrystalline samples with critical temperatures Tc^local = 46 - 53 K were investigated. Two superconducting gaps, the large Delta_L = 10.5 ± 2 meV, and the small one Delta_S = 2.3 ± 0.4 meV were clearly observed at T = 4.2 K. The 2Delta_L/kTc^local = 5.5 ± 1 ratio gives support to the strong coupling mechanism which is responsible for the high Tc value. Temperature dependence of the large gap Delta_L(T) indicates the presence of intrinsic proximity effect (in k-space) between two superconducting condensates.