Doping - dependent anisotropic superconducting gap in Na${}_{1-\hat{I}´}$(Fe${}_{1-x}$Co${}_x$)As

K. Cho, M. A. Tanatar, N. Spyrison +5

The London penetration depth was measured in single crystals of self-doped Na${}_{1-\hat{I}´}$FeAs (from under - to optimal - doping, $T_c$ from 14 to 27 K) and electron-doped Na(Fe$_{1-x}…