  We report results of 75As nuclear magnetic resonance (NMR) experiments on a
self-flux grown high-quality single crystal of SrFe2As2. The NMR spectra
clearly show sharp first-order antiferromagnetic (AF) and structural
transitions occurring simultaneously. The behavior in the vicinity of the
transition is compared with our previous study on BaFe2As2. No significant
difference was observed in the temperature dependence of the static quantities
such as the AF splitting and electric quadrupole splitting. However, the
results of the NMR relaxation rate revealed difference in the dynamical spin
fluctuations. The stripe-type AF fluctuations in the paramagnetic state appear
to be more anisotropic in BaFe2As2 than in SrFe2As2.
