Review of nuclear magnetic resonance studies on iron-based superconductors

The newly discovered iron-based superconductors have triggered renewed enormous research interest in the condensed matter physics community. Nuclear magnetic resonance (NMR) is a low-energy local probe for studying strongly correlated electrons, and particularly important for high-T_C superconductors. In this paper, we review NMR studies on the structural transition, antiferromagnetic order, spin fluctuations, and superconducting properties of several iron-based high-T_C superconductors, including LaFeAsO_1-xF_x, LaFeAsO_1-x, BaFe₂As₂, Ba_1-xK_xFe₂As₂, Ca_0.23Na_0.67Fe₂As₂, BaFe₂(As_1-xP_x)₂, Ba(Fe_1-xRu_x)₂As₂, Ba(Fe_1-xCo_x)₂As₂, Li_1+xFeAs, LiFe_1-xCo_xAs, NaFeAs, NaFe_1-xCo_xAs, K_yFe_2-xSe₂, and (Tl,Rb)_yFe_2-xSe₂.