Observation of Multi-Gap Superconductivity in GdO(F)FeAs by Andreev Spectroscopy

Abstract

We have studied current-voltage characteristics of Andreev contacts in polycrystalline GdO${}_{0.88}$F${}_{0.12}$FeAs samples with bulk critical temperature $T_c$ = (52.5 \pm 1)K using break-junction technique. The data obtained cannot be described within the single-gap approach and suggests the existence of a multi-gap superconductivity in this compound. The large and small superconducting gap values estimated at T = 4.2K are ΔL = 10.5 \pm 2 meV and ΔS = 2.3 \pm 0.4 meV, respectively.

5 pages, 4 figures, submitted to JETP Letters

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Cited by in corpus (8)

• Break-junction technique in application to layered superconductors (Review article)
• Andreev spectroscopy of iron-based superconductors: temperature dependence of the order parameters and scaling of the ${\Delta }_{L,S}$ with $T_C$
• Experimental study of intrinsic multiple Andreev reflections effect in GdO(F)FeAs superconductor array junctions
• Multiple Andreev reflections spectroscopy of two-gap 1111- and 11 Fe-based superconductors
• Investigation of LiFeAs by means of "Break-junction" Technique
• Multigap Superconductivity in GdFeAsO${}_{0.88}$ Evidenced by SnS-Andreev Spectroscopy
• Estimation of intraband and interband relative coupling constants from temperature dependences of the order parameter for two-gap superconductors
• Study of the Two-Gap Superconductivity in GdO(F)FeAs by ScS-Andreev Spectroscopy