Local magnetic inhomogeneities observed via 75As NMR in Ba(Fe1-xNix)2As2   with H0 {\perp} c-axis
  We present field-swept 75As Nuclear Magnetic Resonance (NMR) measurements in the spin-density wave (SDW) state of Ba(Fe1-xNix)2As2 for x=0.0072. The large single crystals were aligned with the external field H0 perpendicular to the c axis. The spectra are increasingly broadened as a function of doping, and are well fit by a model of a commensurate SDW with local impurities. 
Adam P. Dioguardi, Nicholas apRoberts-Warren, Abigail C. Shockley,   Sergey L. Bud'ko, Ni Ni, Paul C. Canfield, and Nicholas...
cond-mat.str-el