Document Type

Article

Publication Date

2011

Journal or Book Title

Low Temperature Physics

Volume

37

First Page

725

DOI

10.1063/1.3660321

Abstract

In-plane surface Ka-band microwave impedance of optimally dopedsingle crystals of the Fe-based superconductor Ba(Fe0.926Co0.074)2As2 (Tc  = 22.8 K) was measured. Sensitive sapphire disk quasi-optical resonator with high-Tc cuprate conducting endplates was developed specially for Fe-pnictide superconductors. It allowed finding temperature variation of London penetration depth in a form of power law, namely Δλ(T) ∼ Tn with n = 2.8 from low temperatures up to at least 0.6Tc consisted with radio-frequency measurements. This exponent points towards nodeless state with pairbreaking scattering, which can support one of the extended s-pairing symmetries. The dependence λ(T) at low temperatures is well described by one superconducting small-gap (Δ≅0.75 in kTc units, where k is Boltzmann coefficient) exponential dependence.

Comments

The following article appeared in Low Temperature Physics 37 (2011): 725 and may be found at http://dx.doi.org/10.1063/1.3660321.

Rights

Copyright 2011 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.

Copyright Owner

American Institute of Physics

Language

en

File Format

application/pdf

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