  75As NMR measurements were performed as a function of temperature and doping
in (Eu1-xKx)Fe2As2 (x=0,0.38,0.5,0.7) samples. The large Eu2+ moments and their
fluctuations are found to dominate the 75As NMR properties. The 75As nuclei
close to the Eu2+ moments likely have a very short spin-spin relaxation time
(T2) and are wiped out of our measurement window. The 75As nuclei relatively
far from Eu2+ moments are probed in this study. Increasing the Eu content
progressively decreases the signal intensity with no signal found for the
full-Eu sample (x=0). The large 75As NMR linewidth arises from an inhomogeneous
magnetic environment around them. The spin lattice relaxation rate (1/T1) for
x=0.5 and 0.7 samples is nearly independent of temperature above 100K and
results from a coupling to paramagnetic fluctuations of the Eu2+ moments. The
behavior of 1/T1 at lower temperatures has contributions from the
antiferromagnetic fluctuations of the Eu2+ moments as also the fluctuations
intrinsic to the FeAs planes and from superconductivity.
