Disentangling superconducting and magnetic orders in NaFe1−xNixAs using muon spin rotation

Muon spin rotation and relaxation studies have been performed on a “111” family of iron-based superconductors, NaFe1−xNixAs, using single crystalline samples with Ni concentrations x=0, 0.4, 0.6, 1.0, 1.3, and 1.5%. Static magnetic order was characterized by obtaining the temperature and doping dependences of the local ordered magnetic moment size and the volume fraction of the magnetically ordered regions. For x=0 and 0.4%, a transition to a …