2014/07/08 by Hyejin Ryu, F. Wolff-Fabris, J. B. Warren +4
Materials Science · Physics and Astronomy · #Condensed matter physics #Iron-based superconductors research #Materials science #Physics #Physics of Superconductivity and Magnetism #Rare-earth and actinide compounds #Superconductivity #cond-mat.mtrl-sci #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.90.020502
published as Phys. Rev. B 90, 020502 (2014) · 5 pages, 4 figures
openalex publication_date 2014/07/08 · arxiv created 2016/04/22 · arxiv updated 2016/04/25 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report evidence for multiband transport and an insulating low-temperature normal state in superconducting K0.50Na0.24Fe1.52Se2 with Tc\ensuremath≈20 K. The temperature-dependent upper critical field Hc2 is well described by a two-band BCS model. The normal-state resistance, accessible at low temperatures only in pulsed magnetic fields, shows an insulating logarithmic temperature dependence as T\ensuremath→0 after superconductivity is suppressed. This is similar as for high\ensuremath-Tc copper oxides and granular type-I superconductors, suggesting that the superconductor-insulator transition observed in high magnetic fields is related to intrinsic nanoscale phase separation.