https://doi.org/10.1140/epjp/s13360-024-04879-9
Regular Article
Superconducting gap structure of slightly overdoped NaFe
Co
As pnictides: joint SnS-Andreev spectroscopy and specific heat study
1
Ginzburg Center for High-Temperature Superconductivity and Quantum Materials, Lebedev Physical Institute, Russian Academy of Sciences, Leninsky prospekt, 119991, Moscow, Russia
2
Department of Chemistry, Lomonosov Moscow State University, Leninslie Gory, 119991, Moscow, Russia
Received:
3
November
2023
Accepted:
7
January
2024
Published online:
22
January
2024
We present a study of the superconducting order parameter in slightly overdoped alkali-metal-based pnictides NaFeCoAs with 
K using a combination of incoherent multiple Andreev reflection effect (IMARE) spectroscopy of planar SnS-junctions and specific heat measurements. We observe a multiple-gap superconductivity, directly and locally determine the magnitudes 
, characteristic ratios 
, and temperature dependences 
of the superconducting order parameters. Possible momentum dependence of the revealed gaps is discussed. We show that a usage of the characteristic ratios obtained in the IMARE experiment provides a qualitative fit of the extracted temperature dependence of the electronic specific heat 
within the two-band approach using only two free parameters.
Copyright comment Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
